Regulating Valves

Hygienic Process Control

Hygienic Regulating Valves

Unique RV-P and RV-ST regulating valves provide controlled, repeatable modulation of hygienic process streams. By combining a sanitary valve body, pneumatic actuator and position-control system, they support accurate regulation of flow, pressure, temperature and tank level in dairy, beverage, food, pharmaceutical and other hygienic installations.

Flow Control Pressure Regulation Normally Closed / Open Inch & DIN Versions

View OEM Part Numbers Operating Principle Models & Configurations

Valve Families

Unique RV-P and Unique RV-ST

The two regulating-valve families share hygienic construction but are intended for different levels of control accuracy and process complexity.

Unique RV-P — Precision Regulation

Unique RV-P is intended for demanding process loops requiring accurate, repeatable positioning. Its integrated position-control package supports stable modulation across a broad operating range.

High positioning accuracy
Integrated positioner and IP converter
Suitable for pressure, flow, temperature and level loops
Available in Normally Closed and Normally Open versions

Unique RV-ST — Simplified Regulation

Unique RV-ST provides a more economical solution for basic hygienic regulation duties where the process does not require the same level of positioning precision as RV-P.

Cost-effective valve-control package
Suitable for simpler product and utility duties
Basic positioner configuration
Available in Inch and DIN executions

Operating Principle

How a Hygienic Regulating Valve Controls the Process

The valve operates as part of a closed-loop control system. A process measurement is compared with the required setpoint, and the actuator continuously repositions the valve plug until the target condition is maintained.

Measure the Process

A sensor monitors the actual flow, pressure, temperature or tank level.

Compare with the Setpoint

The PLC calculates the difference between the measured value and target value.

Command the Positioner

The control signal is converted into a proportional pneumatic command.

Move the Plug

The actuator repositions the valve stem and plug to increase or reduce the flow area.

Stabilise the Process

The loop continuously corrects the valve position until the process remains stable.

Series Comparison

RV-P vs RV-ST

Selection Factor	Unique RV-P	Unique RV-ST
Primary purpose	Accurate and stable process regulation	Basic and cost-effective regulation
Positioning accuracy	Higher	Suitable for non-critical control duties
Positioner package	Integrated advanced positioner with IP converter	Simplified positioner configuration
Typical variables	Pressure, flow, temperature and tank level	Simple flow or utility regulation
Recommended use	Demanding hygienic process loops	Standard hygienic product and water duties
Available executions	Inch / DIN · NC / NO	Inch / DIN · NC / NO

Valve Construction

Main Components

Pneumatic Actuator

Converts compressed-air pressure into controlled linear motion.

Positioner

Compares requested and actual valve positions and corrects deviation.

IP Converter

Converts an electrical control signal into proportional air pressure.

Valve Stem

Transfers actuator movement to the internal plug.

Valve Plug

Changes the effective flow area and regulates process flow.

Seat

Provides the sealing and throttling surface for the valve plug.

Hygienic Body

Product-contact pressure boundary manufactured for sanitary processing.

Product Seals

EPDM and compatible elastomers isolate the hygienic product zone.

Typical Applications

Where Regulating Valves Are Used

Flow Control

Adjusting product or utility flow to meet production setpoints.

Pressure Regulation

Maintaining line pressure, vessel pressure or back-pressure.

Temperature Control

Modulating heating or cooling media in heat-exchange systems.

Tank-Level Control

Controlling inlet or outlet flow to stabilise a defined tank level.

CIP Regulation

Controlling cleaning-liquid pressure or flow during CIP cycles.

Hygienic Utilities

Regulation of process water and compatible sanitary liquid utilities.

Selection Guide

Data Required Before Ordering

Pipe size alone is not sufficient. The operating point, flow coefficient, fail position, connection standard and control package must all be verified.

Process & Hydraulic Data

Required flow rate and normal operating range
Kv value and expected valve opening
Inlet pressure, outlet pressure and differential pressure
Product density and viscosity
Operating, CIP and SIP temperatures

Valve Configuration Data

Unique RV-P or Unique RV-ST
Normally Closed (NC) or Normally Open (NO)
Inch or DIN welding-end connection
Body material and seal material
Control signal, actuator and positioner version

OEM reference tables follow: Parts 2–4 contain the original Tetra Pak / Alfa Laval Unique RV-P and RV-ST configurations shown in the supplied manufacturer screenshots, including exact denominations, connection sizes, Kv values, fail positions and OEM part numbers.

OEM Reference Tables

Unique RV-P Inch — OEM Part Numbers

Tetra Pak / Alfa Laval reference tables for electro-pneumatic Unique RV-P hygienic regulating valves with inch welding-end connections. The exact valve denomination, Kv value, fail position and OEM part number shown in the supplied manufacturer screenshots are reproduced below.

24 Total Unique RV-P Inch OEM references

12 Normally Closed (NC) configurations

12 Normally Open (NO) configurations

Valve series Unique RV-P hygienic regulating valve

Actuation Electro-pneumatic actuator

Material and seals 1.4404 (316L) · EPDM seals

Connection Welding ends · EN 10357-D inch series

Unique RV-P Inch — Normally Closed (NC)

Electro-pneumatic actuator · 1.4404 (316L) · Welding ends · EPDM seals

12 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 38	38	0.5	6-9615 22 3111
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 38	38	1.0	6-9615 22 3112
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 38	38	2.0	6-9615 22 3113
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 38	38	4.0	6-9615 22 3114
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 38	38	8.0	6-9615 22 3115
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 38	38	16	6-9615 22 3116
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 51	51	25	6-8010001806
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 51	51	32	6-9615 22 3117
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 63.5	63.5	40	6-8010001811
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 63.5	63.5	64	6-9615 22 3118
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 76.1	76.1	75	6-9615 22 3119
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-D 101.6	101.6	110	6-9615 22 3120

Unique RV-P Inch — Normally Open (NO)

Electro-pneumatic actuator · 1.4404 (316L) · Welding ends · EPDM seals

12 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 38	38	0.5	6-9615 22 3101
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 38	38	1.0	6-9615 22 3102
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 38	38	2.0	6-9615 22 3103
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 38	38	4.0	6-9615 22 3104
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 38	38	8.0	6-9615 22 3105
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 38	38	16	6-9615 22 3106
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 51	51	25	6-8010001808
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 51	51	32	6-9615 22 3107
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 63.5	63.5	40	6-8010001812
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 63.5	63.5	64	6-9615 22 3108
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 76.1	76.1	75	6-9615 22 3109
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-D 101.6	101.6	110	6-9615 22 3110

Reference note: Exactly 24 Unique RV-P Inch OEM part numbers are included in this section: 12 Normally Closed and 12 Normally Open. No additional, completed or inferred part numbers have been added.

OEM Reference Tables

Unique RV-P DIN — OEM Part Numbers

Tetra Pak / Alfa Laval reference tables for electro-pneumatic Unique RV-P hygienic regulating valves with DIN welding-end connections. The exact denomination, Kv value, fail position and OEM part number shown in the supplied manufacturer screenshots are reproduced below.

24 Total Unique RV-P DIN OEM references

12 Normally Closed (NC) configurations

12 Normally Open (NO) configurations

Valve series Unique RV-P hygienic regulating valve

Actuation Electro-pneumatic actuator

Material and seals 1.4404 (316L) · EPDM seals

Connection Welding ends · EN 10357-A DIN series

Unique RV-P DIN — Normally Closed (NC)

Electro-pneumatic actuator · 1.4404 (316L) · Welding ends · EPDM seals

12 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN40	DIN40	0.5	6-9615 22 3211
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN40	DIN40	1.0	6-9615 22 3212
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN40	DIN40	2.0	6-9615 22 3213
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN40	DIN40	4.0	6-9615 22 3214
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN40	DIN40	8.0	6-9615 22 3215
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN40	DIN40	16	6-9615 22 3216
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN50	DIN50	25	6-8010001809
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN50	DIN50	32	6-9615 22 3217
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN65	DIN65	40	6-8010001813
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN65	DIN65	64	6-9615 22 3218
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN80	DIN80	75	6-9615 22 3219
Unique RV-P	Normally Closed (NC)	Valve, RVP NC Welded EN 10357-A DIN100	DIN100	110	6-9615 22 3220

Unique RV-P DIN — Normally Open (NO)

Electro-pneumatic actuator · 1.4404 (316L) · Welding ends · EPDM seals

12 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN40	DIN40	0.5	6-9615 22 3201
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN40	DIN40	1.0	6-9615 22 3202
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN40	DIN40	2.0	6-9615 22 3203
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN40	DIN40	4.0	6-9615 22 3204
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN40	DIN40	8.0	6-9615 22 3205
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN40	DIN40	16	6-9615 22 3206
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN50	DIN50	25	6-8010001810
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN50	DIN50	32	6-9615 22 3207
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN65	DIN65	40	6-8010001814
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN65	DIN65	64	6-9615 22 3208
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN80	DIN80	75	6-9615 22 3209
Unique RV-P	Normally Open (NO)	Valve, RVP NO Welded EN 10357-A DIN100	DIN100	110	6-9615 22 3210

Reference note: Exactly 24 Unique RV-P DIN OEM part numbers are included in this section: 12 Normally Closed and 12 Normally Open. No additional, completed or inferred part numbers have been added.

OEM Reference Tables

Unique RV-ST Inch & DIN — OEM Part Numbers

Tetra Pak / Alfa Laval reference tables for Unique RV-ST hygienic regulating valves with basic positioner, non-maintainable actuator, 1.4404 (316L) material, welding-end connections and EPDM seals. Inch and DIN versions are listed below in Normally Closed and Normally Open executions.

33Total RV-ST OEM references

9Inch Normally Closed

9Inch Normally Open

8DIN Normally Closed

7DIN Normally Open

Valve series Unique RV-ST hygienic regulating valve

Control package Basic positioner · Non-maintainable actuator

Material and seals 1.4404 (316L) · EPDM seals

Connections EN 10357-D Inch and EN 10357-A DIN welding ends

RV-ST Inch

EN 10357-D welding-end configurations.

RV-ST Inch — Normally Closed (NC)

Basic positioner · Non-maintainable actuator · 1.4404 (316L) · EPDM

9 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 38	38	4.0	6-9613 35 9619
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 38	38	10	6-9613 35 9621
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 38	38	16	6-9613 34 2868
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 38	38	25	6-9613 34 2387
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 51	51	9.0	6-9613 34 2389
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 51	51	34	6-9613 34 2425
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 63.5	63.5	106	6-9613 34 2503
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 76.1	76.1	100	6-9613 34 2494
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-D 101.6	101.6	164	6-9613 35 3049

RV-ST Inch — Normally Open (NO)

Basic positioner · Non-maintainable actuator · 1.4404 (316L) · EPDM

9 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 38	38	4.0	6-9613 35 9642
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 38	38	10	6-9613 35 9644
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 38	38	16	6-9613 34 2672
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 38	38	25	6-9613 34 2774
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 51	51	9.0	6-9613 34 2457
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 51	51	34	6-9613 34 2775
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 63.5	63.5	106	6-9613 34 2743
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 76.1	76.1	100	6-9613 33 4394
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-D 101.6	101.6	164	6-9613 34 4107

RV-ST DIN

EN 10357-A DIN welding-end configurations.

RV-ST DIN — Normally Closed (NC)

Basic positioner · Non-maintainable actuator · 1.4404 (316L) · EPDM

8 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN40	DN40	4.0	6-9613 35 9625
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN40	DN40	10	6-9613 35 9623
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN40	DN40	16	6-9613 34 2514
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN40	DN40	25	6-9613 34 2537
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN50	DN50	9.0	6-9613 34 2560
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN50	DN50	34	6-9613 34 2563
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN65	DN65	10	6-9613 35 2947
Unique RV-ST	Normally Closed (NC)	Valve, RV-ST NC Welded EN 10357-A DN80	DN80	100	6-9613 34 2531

RV-ST DIN — Normally Open (NO)

Basic positioner · Non-maintainable actuator · 1.4404 (316L) · EPDM

7 OEM references

Valve family	Fail position	Denomination	Connection size	Kv	OEM Part No.
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-A DN40	DN40	10	6-9613 35 9647
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-A DN40	DN40	25	6-9613 35 4428
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-A DN40	DN40	16	6-9613 34 4650
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-A DN50	DN50	34	6-9613 34 4874
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-A DN50	DN50	9.0	6-9613 34 3089
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-A DN80	DN80	100	6-9613 33 4410
Unique RV-ST	Normally Open (NO)	Valve, RV-ST NO Welded EN 10357-A DN100	DN100	164	6-9613 34 2589

Reference note: Exactly 33 Unique RV-ST OEM part numbers are included: 18 Inch references and 15 DIN references. No additional or inferred part numbers have been added.

OEM Engineering Guide

Selecting the Correct Hygienic Regulating Valve

Correct valve selection starts with the process duty, not only the pipe size. The valve family, flow coefficient, fail position, connection standard, actuator arrangement and control requirements must all be matched to the real operating conditions before an OEM part number is confirmed.

RV-P vs RV-ST Normally Closed vs Normally Open Inch vs DIN Process Duty OEM Identification

Selection workflow

Five Steps Before Choosing an OEM Part Number

Following this sequence reduces the risk of ordering a valve that fits the line mechanically but performs poorly in operation.

Define the Control Duty

Confirm whether the valve regulates flow, pressure, temperature, level or a utility medium.

Choose the Valve Family

Select RV-P for higher precision or RV-ST for simpler, less demanding control duties.

Confirm Fail Position

Determine whether the valve must fail closed or fail open during loss of air or power.

Verify Connection Standard

Check Inch or DIN execution and match the exact EN 10357 welding-end configuration.

Confirm Kv and OEM Code

Match the selected Kv, size and valve configuration to the correct manufacturer part number.

Step 1

Define the Real Process Requirement

A regulating valve should be selected around the normal operating point, expected control range and process dynamics—not only the maximum flow rate.

Flow-Control Duty

Used where the valve must maintain or vary a target liquid flow rate. Confirm minimum, normal and maximum flow, not only peak demand.

Pressure-Control Duty

Used for line pressure, back-pressure or vessel-pressure regulation. Inlet and outlet pressure values are essential for correct sizing.

Temperature-Control Duty

Common in heating and cooling loops where the valve modulates hot water, chilled water or another heat-transfer medium.

Tank-Level Duty

Used to control vessel inlet or outlet flow and maintain a stable tank level. Response speed and process lag should be considered.

CIP Regulation

Used to regulate cleaning-liquid flow or pressure. Cleaning temperature, chemical compatibility and cycle frequency must be confirmed.

Utility Regulation

Used for hygienic process water and compatible liquid utilities where sanitary materials and cleanability are required.

Step 2

Choose Between Unique RV-P and Unique RV-ST

Choose for precision

Unique RV-P

Recommended when control accuracy, repeatability and stable positioning are important to the process.

Critical flow, pressure, temperature or level loops
Wide operating range
Frequent modulation
Higher positioning accuracy
Integrated positioner and IP converter

Choose for simplicity

Unique RV-ST

Recommended for straightforward control duties where very high positioning precision is not required.

Basic product or utility regulation
Less demanding process loops
Cost-sensitive applications
Simplified positioner arrangement
Standard hygienic control duties

Engineering rule: Select RV-P when unstable control would affect product quality, process safety, heat treatment or line efficiency. Select RV-ST where the process can tolerate a simpler control package.

Step 3

Normally Closed or Normally Open?

The fail position describes the valve’s safe mechanical position when the control air supply is lost.

Configuration	Behavior on air failure	Typical use	Selection question
Normally Closed (NC)	The valve moves toward the closed position.	Common where loss of flow is the safer process condition.	Should product, heating medium or utility flow stop during a failure?
Normally Open (NO)	The valve moves toward the open position.	Used where maintaining flow or pressure relief is safer.	Should the line remain open to protect the process or equipment?

Important: Do not select NC or NO only by copying an old quotation. The correct fail-safe action must be confirmed from the current process safety philosophy, P&ID and operating sequence.

Step 4

Inch or DIN Connection Standard

The OEM tables contain both EN 10357-D Inch and EN 10357-A DIN welding-end versions. These are separate product configurations and should not be treated as interchangeable without checking the line dimensions.

Inch Execution

EN 10357-D welding ends
Typical sizes shown: 38, 51, 63.5, 76.1 and 101.6
Common in installations designed around hygienic inch tubing
Must match actual outside diameter and wall standard

DIN Execution

EN 10357-A welding ends
Typical sizes shown: DN40, DN50, DN65, DN80 and DN100
Common in metric hygienic process installations
Must match the line’s nominal DN and tube dimensions

Step 5

Valve Sizing Philosophy

A control valve should provide stable modulation around the normal operating point. Oversizing can cause hunting, poor response and excessive wear.

Avoid Oversizing

A valve that is too large may operate almost closed during normal production, reducing controllability and increasing sensitivity to small movements.

Check the Kv Range

The selected Kv must support the required flow at the available pressure drop while still allowing useful valve travel during normal operation.

Consider Product Properties

Density, viscosity, temperature and solids content can influence the required valve size and expected control behavior.

Required data

Engineering Checklist Before RFQ

Process Information

Product or utility medium
Minimum, normal and maximum flow rate
Inlet and outlet pressure
Operating and cleaning temperature
Density, viscosity and solids content
Control duty and required response

Valve Configuration Information

RV-P or RV-ST
Normally Closed or Normally Open
Inch or DIN connection
Required size and Kv
Body and seal material
Existing OEM part number or nameplate photo

Next Section: Kv selection, pressure-drop considerations, viscosity, temperature, valve authority, control stability and detailed engineering parameters.

OEM Engineering Guide

Engineering Parameters for Valve Sizing and Stable Control

After the correct valve family, fail position and connection standard are identified, the next stage is to verify the hydraulic and process conditions. Kv, pressure drop, liquid properties, valve authority, control range and cleaning conditions must work together for reliable modulation.

Kv Selection Pressure Drop Valve Authority Viscosity Temperature CIP/SIP

Flow coefficient

Understanding Kv

Kv indicates the flow capacity of a valve. For water-like liquids, it is commonly expressed as the flow in cubic metres per hour through the valve at a pressure drop of 1 bar under defined conditions.

Basic liquid-sizing relationship

Q = Kv × √(ΔP / SG)

Where Q is flow rate, Kv is the valve flow coefficient, ΔP is the pressure drop across the valve and SG is the liquid specific gravity relative to water.

This simplified relationship is useful for initial screening. Final sizing should also consider viscosity, cavitation risk, flashing, noise, process dynamics and the manufacturer’s sizing method.

Typical Kv values in the OEM tables

The regulating-valve references on this page include a wide range of Kv values for different body sizes and trim configurations.

0.5Very low flow

1Low flow

2Low-medium flow

4Moderate flow

8–10Medium duty

16–25Higher flow

32–40Large duty

64–75High capacity

100–164Very high capacity

Sizing quality

Why the Normal Operating Point Matters

A regulating valve should operate through a useful part of its travel during normal production. A valve that remains nearly closed or nearly fully open for most of the cycle will usually deliver poor control.

Too little valve travel

Poor resolution

Useful control region

Preferred

Near full opening

Limited reserve

Oversized Valve

May operate at very low travel, causing hunting, poor repeatability, excessive seat wear and unstable process response.

Correctly Sized Valve

Provides useful stroke during normal operation, stable control and sufficient capacity for expected production variation.

Undersized Valve

May remain near fully open, restrict the process and leave little capacity for peak-flow conditions or future changes.

Hydraulic conditions

Pressure Drop Across the Valve

Pressure drop is one of the most important sizing inputs. It influences the required Kv, valve authority, control quality and risk of damaging flow phenomena.

Condition	Possible effect	Engineering response
Pressure drop too low	The valve may have weak authority and limited influence over the total system flow.	Review line losses, pump head and whether the selected valve is oversized.
Pressure drop appropriate	The valve can modulate the process with stable response over a useful operating range.	Confirm the selected Kv at minimum, normal and maximum process conditions.
Pressure drop very high	May increase noise, velocity, erosion, cavitation risk or product damage.	Check pressure recovery, liquid temperature, vapour pressure and trim suitability.
Variable pressure drop	The same valve position may produce different flow rates as the system conditions change.	Evaluate the full operating envelope and control-loop response.

Control stability

Valve Authority

Valve authority describes how much of the total controlled-circuit pressure drop occurs across the control valve. Very low authority often results in poor control and nonlinear response.

Low authority The valve has little influence compared with the rest of the system resistance. Control may become sensitive and unstable.

Balanced authority The valve has sufficient pressure drop to regulate effectively without creating unnecessary energy loss.

Excessive authority The valve dominates the circuit pressure drop, which may increase pumping demand and create high local velocities.

Practical point: Valve authority should be checked together with pump selection, line resistance, heat exchanger pressure loss and other equipment in the controlled circuit.

Product properties

Density, Viscosity and Solids Content

Density

Density affects the relationship between flow, Kv and pressure drop. Water-based products may be close to SG 1.0, while concentrated products can differ significantly.

Viscosity

High-viscosity liquids may require a larger effective flow area than water-based sizing suggests. Viscosity correction may be necessary.

Particles and Fibres

Suspended solids, fruit pieces, fibres or crystallising products can affect trim selection, cleanability, wear and risk of blockage.

Thermal conditions

Operating Temperature and Cleaning Temperature

Product temperature and CIP temperature should be evaluated separately. The seal material, actuator environment and valve body must tolerate both.

Normal Production Temperature

Confirm continuous operating temperature
Check product expansion and viscosity changes
Consider pasteurisation or UHT process conditions
Verify positioner and actuator ambient limits

CIP or SIP Temperature

Confirm maximum cleaning temperature
Check chemical concentration and exposure time
Verify EPDM or alternative seal compatibility
Consider thermal cycling frequency

Cleaning compatibility

CIP/SIP and Hygienic Design Considerations

Check point	Why it matters	What to confirm
Seal compatibility	Cleaning chemicals and heat can shorten seal life if the elastomer is unsuitable.	Seal grade, detergent type, acid/alkali concentration and temperature.
Drainability	Incorrect orientation can leave product or cleaning liquid trapped in the body.	Installation angle, flow direction and body orientation.
Cleaning velocity	Insufficient velocity may reduce cleaning effectiveness around the seat and body.	CIP flow, line velocity and cleaning-cycle design.
Thermal cycling	Repeated heating and cooling affect seals, clamps, actuator parts and positioner stability.	Cycle frequency, peak temperature and cooling rate.

Dynamic performance

Control Stability and Response

Positioner Resolution

The positioner should move the valve accurately in small increments without sticking, overshoot or excessive deadband.

Actuator Sizing

The actuator must provide enough force to overcome differential pressure, seal friction and spring force under all operating conditions.

Control-Loop Tuning

Even a correctly sized valve can perform poorly if the controller settings, signal filtering or process measurement are unsuitable.

Final verification

Engineering Data Required for Final Sizing

Hydraulic Data

Minimum, normal and maximum flow rate
Upstream pressure at each operating point
Downstream pressure at each operating point
Available pump head
Static and dynamic line losses

Process and Control Data

Product density and viscosity
Operating and CIP temperature
Control objective and required accuracy
Fail-safe action
Positioner signal and automation standard

Important: The OEM part-number tables are reference tools, not a substitute for engineering sizing. Two valves with the same connection size may have different Kv values, fail positions, actuators or control packages.

Next Section: OEM ordering guide, nameplate identification, part-number verification, documentation requirements, spare-parts strategy and common ordering mistakes.

OEM Engineering Guide

OEM Ordering, Identification and Verification Guide

The final ordering stage should confirm that the selected OEM part number matches the exact valve family, fail position, connection standard, size, Kv, actuator, positioner and material configuration. A single missing detail can result in a mechanically incompatible or operationally incorrect valve.

Nameplate Identification OEM Part Number Configuration Verification RFQ Documentation Spare-Parts Planning

Ordering workflow

Six Checks Before Releasing a Purchase Order

This workflow helps maintenance, engineering and purchasing teams verify the valve before an order is placed.

Identify the Existing Valve

Collect the nameplate, full-body photos, connection dimensions and installation details.

Confirm the Valve Family

Verify whether the installed valve is RV-P, RV-ST or another regulating-valve design.

Check the Configuration

Confirm NC or NO, Inch or DIN, size, Kv, seals, actuator and positioner.

Verify the OEM Code

Match the complete configuration to the corresponding manufacturer part number.

Review Documentation

Check quotation description, material requirements, certificates and delivery scope.

Approve the Order

Obtain engineering confirmation before the purchase order is released.

Identification

What to Photograph and Record

Clear identification data is especially important when the OEM number is missing, unreadable, obsolete or linked to a custom line configuration.

Valve Nameplate

Photograph the complete nameplate in focus and record every readable code, serial number, type designation and pressure or temperature marking.

Complete Valve Assembly

Take front, rear and side views showing the body, actuator, positioner, air connections and installation orientation.

Connection Dimensions

Record the outside tube diameter, nominal size, welding ends and any reducers or adapters installed near the valve.

Actuator and Positioner

Photograph actuator labels, positioner type, signal interface, air ports and control-head markings separately.

Process Location

Note the equipment served by the valve, line number, medium, control duty and whether it is on the product or utility side.

Existing Documentation

Collect the P&ID, equipment manual, spare-parts list, old invoice, commissioning file or previous OEM quotation.

Configuration match

Details That Must Match the OEM Part Number

Verification item	Examples	Risk if incorrect
Valve family	Unique RV-P or Unique RV-ST	Different control package, actuator arrangement or performance.
Fail position	Normally Closed or Normally Open	Unsafe valve movement during air or power failure.
Connection standard	EN 10357-D Inch or EN 10357-A DIN	Incorrect tube dimensions or inability to weld into the line.
Connection size	38, 51, 63.5, 76.1, 101.6 or DN40–DN100	Mechanical mismatch with the existing pipeline.
Kv value	0.5 through 164 depending on configuration	Poor control, insufficient capacity or severe oversizing.
Material and seals	1.4404 / 316L and EPDM or project-specific alternative	Reduced chemical resistance, hygiene risk or premature seal failure.
Actuator and positioner	Maintainable or non-maintainable actuator; basic or integrated positioner	Incorrect automation interface or insufficient actuator force.

OEM-code verification

How to Verify a Part Number Correctly

Use the Full Manufacturer Description

A part number should be checked together with its complete denomination, including valve type, fail position, welding standard, connection size and Kv.

Valve family NC / NO Inch / DIN Size Kv Material

Check Number Formatting

Preserve spaces, hyphens and leading digits exactly as shown in the OEM source. Do not shorten or “clean up” the code in a way that changes its identity.

Some ERP systems remove spaces automatically. The purchasing record should retain the original manufacturer code in a separate text field.

Never infer a missing OEM part number. If the code cannot be verified from the manufacturer source, nameplate, manual or confirmed quotation, request technical identification instead of creating an approximate reference.

RFQ package

Information to Include in a Quotation Request

Minimum Identification Data

OEM part number, if available
Complete valve denomination
RV-P or RV-ST family
NC or NO configuration
Inch or DIN connection and size
Kv value
Quantity required

Technical and Commercial Data

Product medium and process duty
Operating pressure and temperature
Seal material requirement
Positioner signal and actuator details
Certificate requirements
Required delivery date
Requested delivery terms

Documentation

Documents to Request With the Quotation

Technical Datasheet

Confirm the exact valve configuration, dimensions, pressure range, temperature limits, materials and automation package.

Material Documentation

Request material certificates and elastomer compliance documents when required by the project or end-user quality system.

Scope of Supply

Confirm whether the quotation includes the complete valve, actuator, positioner, fittings, accessories and commissioning parts.

Dimensional Drawing

Review installation length, height, actuator clearance and welding-end dimensions before approving the order.

Spare-Parts List

Obtain recommended service kits, seals and wear parts for preventive maintenance and future shutdown planning.

Lead Time and Origin

Confirm production lead time, dispatch point, country of origin and packaging method before commercial approval.

Common mistakes

Ordering Errors to Avoid

Common mistake	Why it happens	Corrective action
Ordering by pipe size only	The valve body appears to match the line.	Verify Kv, fail position, family and control package.
Confusing Inch and DIN	Nominal sizes look similar in purchasing records.	Check the actual tube outside diameter and EN 10357 execution.
Ignoring NC or NO	The previous quote lists only a valve size.	Confirm the required fail-safe action from the P&ID and process logic.
Assuming the same Kv for the same body size	Different trims are not visible externally.	Match the exact OEM denomination and Kv value.
Using an internal warehouse code as OEM code	ERP records do not distinguish code types.	Request the original manufacturer reference or supporting document.
Not checking included accessories	The quotation says “valve” without defining the package.	Confirm actuator, positioner, fittings and electrical interface explicitly.

Spare-parts strategy

Plan Beyond the Complete Valve

Critical Installed Base

Create an equipment register containing OEM number, serial number, location, size, Kv, fail position and service history.

Recommended Service Kits

Keep approved seal kits and high-wear parts for valves that are critical to pasteurisation, CIP, utilities or continuous production.

Standardisation

Where engineering permits, reduce unnecessary variety in seals, positioners and actuator configurations to simplify inventory.

Best practice: Store the OEM part number together with the complete technical description. A number without configuration data is difficult to verify years later when the equipment is modified or the original documentation is missing.

Need Help Identifying a Regulating Valve?

Send LGN the existing OEM code, valve denomination, nameplate photo, full assembly images and available process information. The data can then be checked against the relevant RV-P or RV-ST configuration before quotation.

Recommended attachment package

Nameplate close-up
Complete valve photos
Connection dimensions
Actuator and positioner labels
P&ID or line reference
Required quantity

Next Section: preventive maintenance, inspection intervals, common failure symptoms, troubleshooting, calibration and spare-parts planning.

Preventive Maintenance & Troubleshooting Guide

Routine inspection and preventive maintenance help maintain control accuracy, reduce unexpected downtime and extend the service life of hygienic regulating valves. The recommendations below apply to both Unique RV‑P and RV‑ST valve families.

Recommended Preventive Maintenance

Daily / Weekly

Check for external leakage.
Verify smooth actuator movement.
Inspect pneumatic air supply.
Listen for abnormal vibration or noise.

Monthly

Inspect air fittings and tubing.
Check valve response to control signal.
Verify positioner calibration.
Inspect CIP performance.

Shutdown Inspection

Inspect seat and plug wear.
Replace worn seals.
Inspect actuator springs.
Confirm body cleanliness.

Typical Wear Components

Valve Seat

Inspect for erosion, scratches and sealing damage.

Valve Plug

Check guiding surfaces and control trim for wear.

EPDM Seals

Replace if swollen, cracked or permanently deformed.

Positioner

Verify feedback accuracy and pneumatic connections.

Troubleshooting Guide

Symptom	Possible Cause	Recommended Action
Valve hunts continuously	Oversized valve, poor tuning, unstable pressure	Review sizing, tune controller, verify pressure stability.
Valve does not reach setpoint	Incorrect Kv, insufficient actuator force	Verify process data and actuator specification.
External leakage	Damaged seal or loose connection	Inspect and replace seals, tighten fittings.
Slow response	Restricted air supply or sticking mechanism	Check air pressure, clean moving components, recalibrate.
Unstable process control	Low valve authority or poor PID tuning	Review hydraulic design and controller settings.
Frequent seal failures	Incorrect elastomer or aggressive CIP conditions	Verify chemical compatibility and cleaning temperature.

Calibration Recommendations

Calibrate after replacing actuator or positioner.
Confirm full stroke before returning to service.
Document zero and span settings.
Verify response under process conditions.

Keep calibration records for critical production lines.
Recheck after major maintenance shutdowns.
Use clean, dry instrument air.
Confirm fail-safe action after calibration.

Spare-Parts Planning

Critical Item	Recommendation
Seal Kits	Keep stock for all critical production valves.
Positioners	Maintain at least one tested spare for important control loops.
Actuator Repair Kits	Store according to plant criticality and maintenance strategy.
Complete Valve	Consider one standby assembly for high-availability lines.

Best practice: Record every maintenance activity, calibration, seal replacement and actuator repair in the equipment history. Historical records help predict wear patterns, optimize spare-parts inventory and reduce unexpected downtime.

Next: Professional FAQ, SEO content and RFQ Call-to-Action.

Frequently Asked Questions & RFQ Guide

This section answers the most common engineering and purchasing questions about hygienic regulating valves and helps users prepare an accurate quotation request.

What is the difference between RV‑P and RV‑ST?

RV‑P is intended for higher control accuracy and demanding process regulation, while RV‑ST is typically selected for standard hygienic control applications with simpler requirements.

How do I choose Normally Closed or Normally Open?

Select the fail-safe position according to the process safety philosophy and the required valve behavior during loss of air or power.

Can the same valve body have different Kv values?

Yes. Connection size alone does not determine flow capacity. Always verify the Kv value and trim configuration.

What information is required for an OEM quotation?

Provide the OEM part number (if available), valve family, NC/NO configuration, Inch or DIN execution, size, Kv, actuator details, process conditions and photographs of the existing valve.

Can LGN identify a valve without the OEM number?

In many cases, yes. A clear nameplate photo, overall assembly images and process information are often sufficient for technical identification.

Should seal material always remain the same?

Seal material should be selected according to the product, CIP chemicals and operating temperature. Changes should be reviewed by engineering.

Why is valve sizing so important?

An oversized or undersized regulating valve can reduce control quality, increase wear and affect overall process stability.

Are Inch and DIN valves interchangeable?

No. Always verify the applicable EN 10357 standard and actual tube dimensions before ordering.

How often should regulating valves be inspected?

The inspection interval depends on process criticality, operating hours and CIP frequency, but routine preventive maintenance is recommended throughout the year.

Which documents should accompany a purchase order?

Technical datasheets, dimensional drawings, material certificates (if required), scope of supply and confirmed OEM references should accompany the order.

Request OEM Regulating Valve Support

To receive the correct OEM regulating valve or spare part, include as much technical information as possible:

Valve Identification
OEM part number, nameplate and serial number.

Configuration
RV‑P / RV‑ST, NC / NO, Inch / DIN, connection size and Kv.

Process Data
Medium, pressure, temperature, flow rate and control duty.

Documentation
Photos, P&ID reference, previous quotation or equipment manual.

LGN supplies OEM hygienic regulating valves and spare parts for food, dairy, beverage, pharmaceutical and hygienic processing industries. Our engineering team can assist with OEM identification, technical verification and equivalent replacement selection before quotation.

Technical Support & RFQ

Need Help Selecting the Right Regulating Valve?

LGN supports OEM identification, technical verification and sourcing of hygienic regulating valves, complete assemblies, actuators, positioners, seal kits and replacement components for food, dairy, beverage, pharmaceutical and sanitary processing applications.

Engineering Support

Send Us Your Process Data or Existing Valve Information

For a new regulating-valve application, provide the required flow, upstream and downstream pressure, product properties, temperature, connection standard, fail-safe action and automation requirements. For replacement valves or spare parts, include the complete OEM part number, nameplate, photographs and key dimensions whenever available.

✓ OEM part-number and installed-valve identification

✓ RV-P and RV-ST configuration verification

✓ Kv, flow and differential-pressure review

✓ Actuator, positioner and fail-safe selection support

✓ Seal-kit and preventive-maintenance recommendations

✓ Worldwide industrial sourcing and supply support

Request a Quotation Contact LGN

For Faster Technical Evaluation

Include as many details as possible in your inquiry.

# OEM Part Number Include the complete manufacturer reference and valve denomination.
V Valve Family and Fail Position Specify RV-P or RV-ST and Normally Closed or Normally Open.
K Kv and Flow Data Provide minimum, normal and maximum flow and the required Kv if known.
Ø Connection Details Specify Inch or DIN execution, nominal size and actual tube diameter.
P Pressure and Temperature Include upstream pressure, downstream pressure and operating/CIP temperature.
A Automation Requirements Confirm actuator type, fail-safe action, positioner and control signal.
▣ Valve Photographs Provide the nameplate, full assembly, actuator, positioner and connection ends.
D Existing Documentation Attach P&ID references, old quotations, drawings or maintenance records.

How Lian Giti Namdar Can Support Your Regulating Valve Requirement

Accurate identification and complete process data reduce the risk of ordering an incorrect valve, actuator, positioner, spare part or service kit.

OEM Valve Identification

Review of valve type, size, fail position, connection standard, Kv, actuator, positioner, nameplate information and installed configuration.

Selection Data Review

Evaluation of flow, upstream and downstream pressure, product density, viscosity, temperature, valve authority and process-control duty.

Service-Kit Sourcing

Identification of compatible seal kits, elastomers, wear parts, actuator repair components and preventive-maintenance items.

Replacement Components

Support for actuators, positioners, pneumatic accessories, control components, welding ends and complete replacement valve assemblies.

Hygienic Process Industries

Regulating valves are used where stable flow, pressure, temperature or level control must be combined with cleanable construction and hygienic product handling.

Dairy Processing Food Production Beverage Lines Pharmaceutical Biotechnology Cosmetics CIP Systems Utility Control

Prepare a Complete Regulating Valve RFQ

Send the OEM reference, valve photographs, RV-P or RV-ST family, NC or NO configuration, Inch or DIN standard, connection size, Kv, process medium, flow, pressure, temperature, actuator details, positioner requirements and requested quantity. LGN will review the available information before quotation.

Request Technical Proposal