What is a PRV?

What is a PRV?

Let’s begin by getting this out of the way:

What is a PRV?

A PRV or Pressure Reducing Valve is designed to open and relieve pressure at a set pressure point. Not to be confused with a pressure relief valve, PRV’s are designed to take higher pressure and reduce it down to a lower pressure.

Now that you know what it is and learning that you may need one for your process, how do you pick out the PRV for you? At Apex, we recommend Watson McDaniel brand PRVs. Here’s why:

  1. Watson brand PRVs are robustly designed to handel the toughest steam services.
  2. Watson PRVs can utilize Spence brand Pilots or Watson can supply a pilot made for Spence valves. Interchangeability is a huge convenient factor for those who keep different brands in their facility.
  3. Watson PRVs are dimensionally equivalent to Spence. They even have the same face-to-face dimension. That means changing out a Spence for a Watson is very easy.
  4. Watson PRVs are made of ductile iron making them less expensive than cast steel.
  5. Watson products are USA MADE AND INVENTORY! They are made right at home in Pottstown, PA. And with millions of dollars of inventory on the shelf – we can deliver to you quickly.
  6. Every PRV comes with a custom sizing sheet to show you exactly how you can expect your valve to perform.

Picking Your PRV

Watson McDaniel offers a wide range of different PRVs for you to choose from. Direct operated regulators are typically the most economical and can be a suitable choice particularly in the low to medium flow range. Pilot Operated Regulators, such as the HD-Series will control downstream pressure more accuratly over a wider range of flows. Let’s learn more about them.

HD Series Pilot Operated Regulating Valves

HD Series – Pilot Operated

1/2″ – 6″ • Ductile Iron Body

Used for pressure reduction or temperature control applications depending on pilot selection. Commonly used for reducing steam pressure to a specific downstream set pressure, other pilots are also available for controlling temperature, back pressure, and other applications.



1/2″ – 2″ • Ductile Iron or Stainless Steel Body

Simplest and most economical choice for Pressure Reducing applications for a variety of fluids including Steam, Water, Air, and other liquids and gases. These direct operated regulators have limited capacity compared to the HD-Series pilot operated regulators.


Direct Operated Pressure Regulators

455 Series

1/2″ – 4″ • Bronze / Cast Iron Body

For reducing pressure on Steam & Air applications. An external pressure sensing connection is required. The lack of small pilot orifices make the 455 Series less susceptible to dirt and scale. Balanced seat and disc design allows these valves to be used in applications with low inlet pressure down to 5 psig.


Pilot Operated Pressure Regulating Valves

403 Series – Pilot Operated Reduction

1/2″ – 4″ • Ductile Iron Body

The 403 are pilot-operated, piston-actuated, pressure regulators primarily used for reducing pressure in STEAM systems. Available with an optional internal sensing line which simplifies installation. Piston Operated regulators are more compact in size when compared to typical diaphragm actuated regulators.



1/2″ – 4″ • Bronze / Cast Iron Body

These are the primary choice for reducing pressure on Water, Air, and other liquid and gas applications. The soft-seated elastomeric Viton disc has an operating temperature up to 300ºF and provides excellent shut-off characteristics. The balanced seat design eliminates internal forces extending the capability range of both pressure and capacity.


Discover All PRV’s Available From Apex Industrial Solutions


In this article, you will have learned the following:

  • What a PRV is and how it works
  • What brand the Apex team recommends and why
  • Different types of PRVs available for you and how they can fit into your processes

If you have any further questions regarding PRVs or any other parts in your process that can be improved, contact us today!

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