Our most common steam pressure reducing valve models

The following article aims to solve any question about the steam pressure reducing valve, from what it is, what are its characteristics, what it is for and what models exist. 

Pressure reduction is a physical process of thermodynamic transformation that allows to adjust and stabilize the pressure downstream of the process fluid, while increasing the energy upstream. 

These processes of thermodynamics are well known and explored by Valfonta, a Catalan company based in the province of Barcelona that has been manufacturing valves of all kinds since 1961, first as ‘Válvulas Fonta‘ and then giving rise to the current Valfonta. 

How do steam pressure reducing valve systems work?

Assuming that the steam system is well-designed and that it introduces good quality steam, i.e. dry saturated steam at high pressure into the distribution network, a good pressure reduction at the point of use simplifies installation and lowers plant costs. For example, no other equipment is required to control temperature because these and pressure equipment are correlated, and pressure control is sufficient under saturation conditions. 

How do you reduce the pressure of a fluid? By a specific device called a pressure reducer or also a pressure reducing valve for steam. That is, it is a valve that can make an adequate adjustment of the downstream steam pressure and keep it constant at the desired value in a precise, reliable and cost-effective way. 

steam pressure reducing valve

Some applications require pressure regulation upstream of the valve, to keep it constant or to regulate its circulation in distribution lines, causing any excess pressure to ‘discharge’ or, rather, modify or destabilize a process line, to safeguard the integrity of the installed equipment; in this case, we are talking about a pressure relief valve or relief valve. That is why it is critical to make the correct calculation for the application of each vapour pressure reducing valve. 

Categories of steam pressure reducing valves

We can distinguish pressure reducing valves into two broad categories: 

steam pressure reducing valve

Self-operated pressure reducing valves: these are automatic valves that do not require any internal or external power supply at the inlet.

steam pressure reducing valve

Pressure reducing valves operated by a pneumatic or electric actuator: these are those that, to operate, must be externally driven by compressed air or electricity.

Principle of operation of pressure reducing valves for steam

The principle of operation of a pressure reducing valve for automatic steam is based on the continuous comparison of the reduced pressure with the opposite force of an antagonist spring and on the subsequent automatic intervention to restore the desired pressure value downstream, acting on a special elastic element, such as a membrane or diaphragm, which controls the blind directly or indirectly through a ‘pilot’ valve. In the first case, we are talking about a ‘self-acting’ or ‘direct acting’ reducer, in the second case it is more appropriate to talk about a ‘self-servo-appointed’ or ‘servo-controlled’ reducer. 

Utility of steam pressure reducing valves

A pressure reducing valve for steam or other well-sized fluid must always ensure sufficient flow to meet the maximum required under the intended working conditions and possibly in the most difficult conditions. Whenever demand peaks are recorded, the valve partializes the flow of steam to non-critical users to maintain a stable and risk-free supply, both in the boiler and in the lines of critical users. 

Types of steam pressure reducing valves available in the Valfonta catalogue

Valfonta can offer you a wide range of products to offer you, among which the following models stand out:

steam pressure reducing valve

Pressure reducing valve, Model M2: This is a direct action valve, compensated by a membrane or diaphragm, not assisted by auxiliary energy. The valve closes in the face of increased pressure downstream. Ideal for gases, liquids and steam in chemical, bulk storage and pharmaceutical industries. Suitable for controlling gases between temperatures of -10 and +80.

steam pressure reducing valve

Piston pressure reducing valve, Model PRV 20: A pressure reducing valve with external actuator. To balance, it uses a piston to keep the pressure constant and downward, with oscillations in the inlet pressure. It is used in chemical laboratory lines, sanitary plants and sprinkler systems.

steam pressure reducing valve

Self-actuated pressure reducing valves, Model M1: A membrane controls the outlet pressure. Being self-acting, it does not need auxiliary energy. Although it is very suitable for steam equipment, it is also useful in compressed air, non-hazardous gases and liquid applications.

Other models

Self-activated pressure reducing valves: These are several models designed to offer constant pressure as a buffer for inlet pressure oscillations. Specially designed to work with low outlet pressure gases, liquids, and gases of groups 1 and 2, compressed air, steam, nitrogen, fuel, water or neutral gases.

Direct action pressure reducing valves: There are many models of valves of easy regulation that can be installed in any position, there are with membrane or diaphragm, self-actuated or self-compensated. With an expansive field of application, they are usually used in chemical laboratories, sanitary, industrial, steam, for cylinders and vulcanizing presses, furnaces.

Do you require technical advice?

Contact Valfonta‘s experts by writing to us at valfonta@valfonta.com or by calling 933720888. It will be a pleasure to help you choose the steam pressure reducing valve that best suits your needs.