Pressure regulators, also known as pressure-reducing valves, provide a practical solution to pressure rises, which are a major concern in process and building installations. They are self-operated, require no external energy and are available in versions for water, air, steam, gases and other media. Luna Flow Control supplies pressure regulators for temperatures from -200 °C to +700 °C, in sizes from DN 15 to DN 250 and pressure ratings from PN 16 to PN 250.
What Is a Pressure Regulator?
A pressure regulator reduces the pressure in a controlled manner when the pressure in the system rises above the required level. Excessive pressure prevents a system from working properly and can damage pumps, valves and machinery. Without a regulator, equipment may start to leak and then fail, and in extreme cases pipes can burst. Installing a pressure-reducing valve therefore plays an important role in the safety and reliability of the installation.
Working Principle
In a pilot-operated regulator, the adjusting screw opens the pilot valve and allows the controlled medium, such as steam, to enter the valve orifice. When the flow through the pilot exceeds the demand at the control point, pressure builds up under the main diaphragm. Once this pressure overcomes the force of the return spring, the main valve opens. The medium passing through the main valve raises the outlet pressure, which is transmitted under the pilot diaphragm. The pilot valve then throttles until the pressures above and below the diaphragm reach equilibrium, keeping the downstream pressure at the set value.
Types of Pressure Regulators
- Water pressure regulators – the most widely used type; they balance the inlet pressure from the water mains at the required value and protect the system from damage.
- 3-way pressure regulators – compact units that are easy to install at the desired point of the installation.
- 1/2″ and 3/4″ pressure regulators – for smaller installations carrying gas, water, air or chemicals; available in stainless steel, cast iron, ductile iron and bronze.
- Y-type pressure regulators – reduce sudden rises in mains water pressure in a controlled way.
- Air pressure regulators – prevent sudden air pressure increases that can cause equipment failure.
- Fire system pressure regulators – keep pressure within safe limits in firefighting networks.
- Threaded and flanged pressure regulators – selected according to the connection type of the line.
Size Ranges
| Medium / version | Pressure rating | Size range |
|---|---|---|
| Steam | PN 16 – 250 | DN 15 – 200 |
| Steam | PN 16 – 40 | DN 15 – 200 |
| Superheated steam | PN 16 – 160 | DN 20 – 125 |
| Liquids and gases | PN 16 – 40 | DN 15 – 200 |
| All fluids | PN 16 – 250 | DN 15 – 250 |
| Bronze pressure regulators | PN 16 – 40 | DN 15 – 200 |
Application Areas
- Fire protection systems
- Residential and office installations
- Industrial plants and process lines
- Central heating and cooling systems
- Water distribution lines
Selection Tips
Select the regulator according to the medium, the inlet pressure and the required outlet pressure, the flow rate, the operating temperature and the connection type. Correct sizing ensures stable downstream pressure, protects pumps, valves and pipework from sudden pressure changes and extends the life of the entire installation.
