The Importance of Pressure Reducing Valves

Hot water cylinders are utilised in many New Zealand homes. A series of pipes are responsible for the transport of water to your property’s plumbing.  Whether you rely on public water supply or use pumps, water travelling to your property should be regulated to protect your existing fixtures and hot water system. This includes the regulation of water pressure and quality.  

The video above shows just how bad a leak can be when things go wrong. This is an old pressure reducing valve on a low-pressure hot water cylinder that could no longer cope with the incoming pressure. 

Why Are Pressure Reducing Valves So Important ?

In the city, most homes are supplied with a public water main feed. This feed is not pressure regulated, nor is it guaranteed to supply debris free water. This ultimately means that you need to take measures to protect your fixtures and hot water system from the incoming quality and pressure of your public water supply. 

How Does a Pressure Limiting (Reducing) Valve Work?

This Diagram of an Ajax type pressure reducing valve nicely explains what happens to incoming pressure. 

Hot Water Systems

If you have low pressure you will most likely know that there is potential for more pressure. Knowing this, it becomes pretty obvious that there is a device which limits the incoming pressure. This device is a pressure reducing valve and is rated in meters. A common rating is 7.5 meters which in other words means that the pressure is regulated to 7.5 meters of atmospheric pressure. 

 

Those of us that enjoy mains pressure are less concerned about regulating pressure, we may believe that the more pressure the better or that it does not need to be regulated, but is that entirely true?   

Appliance and Fixture Ratings

Your hot water system, your appliances, your taps and even your toilets are all pressure rated and should be regulated. This means that they will only cope with a certain amount of pressure before there is potential for failure. This may include a scenario such as in the above video where there is a high risk for flooding when failure happens. 

Please ask Hot Water Cylinders NZ if you are unsure about how to rate any of your plumbing related fixtures and hot water system. 

Where Do I Install the Pressure Reducing Valve?

Pressure reducing or limiting valves will protect your home and everything connected to your plumbing within. So it makes sense to install this valve as upstream as possible within the plumbing system. Typically this would be directly after the water meter on your public supply. 

Often, with low pressure systems this is not desirable at all because one may still want to enjoy “mains pressure” on the cold but continue to accommodate the low pressure hot water cylinder on the hot side in which case the low pressure reducing valve will only be installed on the cold water inlet of the hot water cylinder. These systems are well known as “unbalanced hot water systems”. Another issue with low pressure valves is that they are large and “bulky” making it difficult to install within a meter box where they are prone to damage and sensitive to pressure fluctuation. 

Every home should be protected from the effects of incoming pressure which can majorly increase without notice. 

If you need advice or are unsure about which valve suits your circumstances best, give us a ring and we can help. Hot Water Cylinders NZ also offer valve replacement and repairs. 

Here a list of valves which we may recommend.

RMC Products

RMC has a variety of pressure reducing valves that cater to your needs. Not only do they have pressure-relieving valves, but they also have a variety of products that go with, or have more features that will make it multifunctional.

Here are some of RMC’s pressure reducing valves:

RMC 4 in 1 Hot Inlet Control Valve c/w Adj Limiting 20mm CV75

 Manufacturer: RMC

 Product Specs:

 The Filling-Group type 2128 is designed to automatically fill and refill central heating installations. The Filling-Group is permanently connected to the heating installation. The connection to the potable water system is made with a hose. When the supply pressure falls below the pressure of the heating installation during the filling operation, the water goes into the potable water system. 

 

RMC Cold Water Expansion Valve 700kpa CE75H-700-KPA

Manufacturer: RMC

This product comes in 2 variations, the RMC Cold Water Expansion Valve 700kpa CE75H- 700-KPA and the RMC Cold Water Expansion Valve 800kpa CE75H- 800-KPA.

RMC Hot Water Cylinder Valve Package

 Manufacturer: RMC

 This pack includes 4 in 1 Control Valve, Pressure Limiting Valve, Tempering Valve, Cold Water Expansion Valve, and Male/Female Ball Valve.

RMC HT575 Pressure & Temp Relief Valve 20mm 850kpa HT705

 Manufacturer: RMC

RMC’s Pressure and Temperature Relief (P & T Relief) Valves are safety controls that ensure that the temperature of the water in a pressurized unvented water heater cannot exceed 99° C in the event that the normal thermostatic controls fail.

These valves may be used to guard against over temperature and over-pressure hazards wherever water is stored in unvented containers. This is a requirement of Australian Standard AS 3500-4. RMC P & T Relief Valves are available in 15 mm and 20 mm configurations.

RMC Low Pressure Reducing Feed Valve 7.6m 76kpa D505NZ

 Manufacturer: RMC

This comes in two variations, RMC Low Pressure Reducing Feed Valve 7.6m 76kpa D505NZ and the RMC Low Pressure Reducing Feed Valve 3.7m 37kpa D503NZ.

RMC Pressure Limiting Valve Adj 15mm 155-550kpa 80deg PRV015

 Manufacturer: RMC

The RMC Pressure Reducing Valve is used in water systems to limit the downstream pressure to the pre-set maximum. It compensates for fluctuating upstream pressure to maintain constant maximum outlet pressure.

This is suitable for demanding commercial and industrial applications and multi-unit dwellings and can be used to reduce pressure upstream of commercial and industrial devices such as dosing apparatuses, high-pressure cleaners, and laboratory equipment.

The RMC Pressure Reducing Valve can deliver high flow rates with minimal head loss. This is available in 15 mm, 20 mm, 25 mm, 32 mm, 40 mm, and 50 mm configurations with female BSP thread connections.

RMC Pressure Limiting Valve Adj 20mm 155-550kpa SYR-310620

 Manufacturer: RMC

A range of economy domestic/light commercial quality pressure reducing valves, suitable for various applications at temperatures up to 40°C (60°C for 1 hour max.) The valves are designed for a low-pressure drop, so minimizing noise levels.

The pressure-balanced diaphragm construction and drop-tight design also ensure constant outlet pressure is maintained across all flow rates and no-flow conditions.

All models feature cartridge construction, fully serviceable strainer and female BSP connections for ease of installation and maintenance and are suitable for use with warm water, fuel oil, compressed air, neutral gases and neutral non-sticking liquids.

Why Choose Hot Water Cylinders NZ?

Here at Hot Water Cylinders NZ, we give you the best quality service and the assurance of world-class products and customer service. We not only provide pressure controllers, but also main pressure cylinders, low-pressure cylinders, gas water heating, and many more. We aim to serve you because you are our priority. That is the type of service you can get with New Zealand’s #1 hot water heating and plumbing specialist.