This document discusses pressure reducing valves (PRVs) and their installation. It provides an agenda that covers an introduction to PRVs, code requirements, types of PRVs including piston operated and diaphragm operated valves, sizing PRVs based on flow requirements and operating pressures, installation configurations such as single regulator and two-stage serial reduction, and common questions about PRVs. The presentation aims to explain how PRVs work to reduce water pressure and protect plumbing systems, and provide guidance on selecting, installing and maintaining PRVs.

1. ADR AUTOMATION
& TECHNOLOGIES
Engineered to flow.
IPPL - 2023
- S. V. RAJA,
Managing Partner
ADR Automation &
Technologies

2.  Introduction
 Valves
 PRV
 Code Requirements
 Types of PRVs
 Selection
 Installation & Configurations
 Q&A
Agenda

3. WhyADR
About us
 Young & Energetic Team
 Specialized in customized automation solutions for utility systems
 Catering to Various segments like Plumbing, HVAC, Fire fighting & Utility
 Technical support from the design stage to execution stage
 After sales service support team
 Master distributor for various leading Brands like
 Lehry Valves
 Aquamet / Zenner water meters & flow meters
 Wika, Mass & H.Guru make pressure gauges & Temperature gauges
 Wika, Switzer & Infos make pressure switch, flow switch & transmitters
 Fiducia Make Level sensors, Level transmitters
 Smart Pump control panels

4. PRODUCTS
PLUMBING PRODUCTS
1. Ball Valves
2. Butterfly Valves
3. Non Return Valves / Check Valve / NRV
4. Strainers
5. Gate Valves / Globe Valves
6. Pressure Reducing / Pressure Relief Valve
7. Solenoid Valves
8. Pneumatic Controlled Valves
9. Electrical Controlled Valves
10. Water Hammer Arrestors
11.Water Meter with BMS compatibility
12.Utility Management Solutions.
( Pump cum Level control system / Water metering system)

5. IPPL - 2023

6. PRESSURE REDUCING VALVE
(PRV)
TODAY TOPIC
Other name:
• Pressure Regulator

7. What is Water Pressure?
• The “push” behind water
• It is measured in ‘Kg/cm2' - one Kg/cm2 is the pressure
needed to raise water to a height of 10 meters.

8. Effects of High Water Pressure
Damage to plumbing
system components
Increased water usage
Energy waste
Solution – Introduce
PRV to main at
constant pressure

9. What is Pressure Reducing Valve?
• The valve which reduces the pressure of water goes
through it, and is used to obtain a regulated and
constant/set pressure at it outlet
• It is installed in the water main which will protects the
whole plumbing systems from problems due to high
pressure

10. History of Pressure Reducing Valve
 In 1876 :
 The first pressure regulator Invented,
manufactured and marketed.
• It was somewhat complicated, took up
a lot of space (nearly 2 meters high),
but it worked.
In 1930 :
Everything was designed – the principle of
the direct action regulator valve with
diaphragm
the general look

11. All National codes say system requires PRV where
water pressure exceeds 4.5 Bar
• IPC Section 604.8
• UPC Section 608.2
• NBC Part 9, Section 2
• IS 9739:1981
Code Requirements

12. Types Of Pressure Reducing Valves
Piston Operated
Diaphragm Operated
Direct Acting Pilot Operated

13. Piston type PRV - basic function
Pressure Reducing Valves–Piston type

14. The outlet pressure acts on the diaphragm:
• the force exerted by the outlet pressure, which tends to close the
plug
• The force exerted by the spring,
which tends to open it.
Compensated seat working principle
Pressure Reducing Valves–Diaphragm type

15. Pilot Circuit
Basic Valve
Automatic Control Valve - PRV
Construction

16. PRV Sizing based on
Pressure Reducing Valve - ACV
SIZING OF PRV
1. Flow Requirements
• PRV Sizing - Min & Max Flow, NOT ON size of the pipe.
• Minimum flow should be 10% - 15% of the maximum flow
rate desired in the system
2. Operating Pressures
• Inlet and Outlet pressure are important Factor
• In a thump rule we can reduce the pressure in 3: 1 ratio
3. Flow curve / Pressure loss curve
• Pressure loss should be fall in between 0.25 to 0.75 bar
Note:
• Properly sized valve prevents noisy operation or premature
failure
• Over sizing can lead to wire draw

17. C zone : No Cavitation, Recomended
B zone: Risk of Cavitation
A zone: Cavitation Zone, Not recomended
Continuous operation in the red cavitation
zone could cause rapid damage of the
internal parts.
Cavitation
SIZING OF PRV
LEHRY VALVES - CHENNAI

18. INSTALLATION - PRV
The Installation
• Arrow of valve body should point
in the direction of flow
• Can be installed horizontally in
the upright or vertically (Beyond
6” vertical not recommended)
depending on serviceability
FLOW DIRECTION

19. • 3 Types of Installation Configurations:
• Single Regulator
• Two-Stage Serial Reduction.
• Parallel / Low flow by-pass.
INSTALLATION - PRV
Installation Configurations

20. The Installation
INSTALLATION - PRV

21. The Installation
INSTALLATION - PRV

22. • Ideal where there is a wide variation in pressure
between inflow pressure and functional pressure needed
in building
• Ideal where supply main pressure exceeds 200psi
Automatic Control Valve - PRV
Two-Stage Serial Reduction Configuration

23. INSTALLATION - PRV
Parallel Installation
Ideal where a wide range of water flow demand at reduced
pressures is required.

24. INSTALLATION - PRV
An Alternative
• Throttles to reduce high
upstream pressure to
constant lower downstream
pressure
• Low flow by-pass controls at
low flows
• Main line controls at high
flows
• Reducing and low flow by-
pass set points are separately
adjustable.

25. PRV STATION

26. PRV STATION

27. Disadvantages
• Regular choking, requires strainers and regular
maintenance
• Inconsistent Downstream pressure and inaccuracy
• High response time.
• Not reliable
Pressure Reducing Valve – Piston type

28. Q&A
IPPL - 2023
IPPL - 2023

29. svraja@adrautomation.com
Cell no: 9382104938
ADR Automation and technologies
IPPL - 2023
www.adrautomation.com