Technical - Gas regulator selection guide

Specialty Gas Equipment for Purified Gases


High purity gases require high purity distribution equipment to prevent contamination as pressure is regulated to working pressure.  You will find single and two stage regulators, purge assemblies, and several other speciality gas products that meet your rigorous high demands for distribution of 99.999 and 99.9999% pure or 5.0 and 6.0 purity gases.  If you don't see what you need, contact Pressure Regulator Malaysia to have us design a system that meets your requirements. 

Choosing a Gas Regulator

With Pressure Regulator Malaysia, you will find help in how to choose a gas / pressure regulator, where to find details on the pressure regulator that meets your needs. The following are some of the most important factors you need to know prior to deciding which gas regulator is right for your application.  While this is not a comprehensive list, it is a good start in determining your pressure regulator choice.  If at any time during the process you need additional help, Pressure Regulator Malaysia would be happy to assist you or answer any other questions you may have. 

Pressure Regulator : Materials of Construction

The materials that make up your pressure regulator or gas regulator are one of the most important factors in selecting a regulator.  Equipment products that are effective for one gas may not be appropriate, or may be very dangerous to use in another gas service.  The properties of the gas determine the materials of construction needed for a pressure regulator to function properly. But as a basic primer, brass pressure regulators are compatible with most non-reactive gases like nitrogen, argon, helium, and compressed air.  316L stainless steel pressure regulators are corrosion resistant and therefor suitable for many of the anhydrous corrosive gases such as nitric oxide (NO) and nitrogen dioxide (NO2). Chrome-plated brass pressure regulators should be treated just like brass regulators. The most common pressure regulator is the nitrogen gas regulator.

Gas regulator : Maintaining Gas Purity
(Forged or Barstock Bodies)

Forged body gas regulators are more economical than barstock gas regulators.  However, the internal wetted surface area is greater and the surface rougher than barstock gas regulator.  These factors add to the increased contamination potential, since evacuation of ambient atmosphere through vacuuming or purging is more difficult.  Barstock gas regulators have all wetted surfaces machined to a smooth finish and have a smaller internal volume.  All these factors apply to brass gas regulator, chrome-plated brass regulator and stainless steel gas regulators. 

Pressure regulator Inlet Pressure Rating

The pressure regulator chosen must be able to handle the gas supply pressure.  Be sure to determine the supply pressure from your gas supplier or from the gas source and use a pressure regulator that can handle that pressure.  When in doubt, contact Pressure Regulator Malaysia. 

Pressure regulator Delivery Pressure Range

The basic object of a pressure regulator is to reduce the supply pressure (either from a cylinder or other gas or liquid supply source) to a level compatible with the system or process in use.  Our increased number of pressure regulator choices just about assures you there is one suitable for your needs in our pressure regulators line. We have the largest selection of pressure regulators in Malaysia.


The most common outlet pressure range is 10 bar (150 psi) and 100 psi (7 bar). 


Some pressure regulator applications require high outlet pressure exceeding (50 bar) 750 psi. This type of pressure regulator is made of piston sensor. Some examples of applications for this type of pressure regulator are nitrogen regulator for purging, laboratory research, airline charging kit, nitrogen regulator for pressure testing,  nitrogen regulator for hydraulic accumulator and chemical manufacturing.


Some pressure regulator applications might just require outlet pressure of 20 bar for example in gas piping installation. Gas piping installation needs to cater to a higher flow rate. Therefore a manifold pressure regulator with a higher flow capabilities will be needed.

Single Stage Pressure Regulator or Dual Stage Regulator? 


Single stage pressure regulators reduce pressure in one step.  If used on a cylinder, you will notice a slight rise in the outlet pressure as cylinder pressure falls with use.  If this is tolerable in your application, or if you are using liquefied gas like propane, then a single stage regulator may be suitable.  They are also suited for situations where the outlet pressure is constantly monitored and adjusted.  


Single-Stage Pressure Regulators reduce pressure by passing through a pressure reducing valve area in one step to deliver a pressure within a specific range. These pressure regulators demonstrate a slight increase in delivery pressure as the cylinder pressure falls during use, also known as “Inlet Pressure Decay.” This reduced Inlet Pressure Decay provides less force against the pessure regulator valve causing it to open wider resulting in increased outlet pressure. 




Diagram showing a single stage pressure regulator 















Dual stage pressure regulators are actually two regulators in one.  They have a nonadjustable first state usually set at 250-300 psig which feeds gas at that reduced pressure to the second stage.  There it is further reduced to the working pressure required.  The result is a constant deliver pressure throughout the usable life of the cylinder.  They are ideally suited to situations where constant delivery pressure is essential. Dual stage pressure regulators are sometimes refer to as multistage pressure regulators or double stage pressure regulators.



 Diagram showing a double stage pressure regulator


















Decaying inlet pressure characteristic of a gas pressure regulator can be explained by the graph below.