What is Pressure regulator: Definition and 21 Discussions

A pressure regulator is a valve that controls the pressure of a fluid or gas to a desired value.
Regulators are used for gases and liquids, and can be an integral device with a pressure setting, a restrictor and a sensor all in the one body, or consist of a separate pressure sensor, controller and flow valve.
Two types are found: The pressure reduction regulator and the back-pressure regulator.

A pressure reducing regulator is a control valve that reduces the input pressure of a fluid or gas to a desired value at its output. It is a normally-open valve and is installed upstream of pressure sensitive equipment.
A back-pressure regulator back-pressure valve, pressure sustaining valve or pressure sustaining regulator is a control valve that maintains the set pressure at its inlet side by opening to allow flow when the inlet pressure exceeds the set value. It differs from an over-pressure relief valve in that the over-pressure valve is only intended to open when the contained pressure is excessive, and it is not required to keep upstream pressure constant. They differ from pressure reducing regulators in that the pressure reducing regulator controls downstream pressure and is insensitive to upstream pressure. It is a normally-closed valve which may be installed in parallel with sensitive equipment or after the sensitive equipment to provide an obstruction to flow and thereby maintain upstream pressure.Both types of regulator use feedback of the regulated pressure as input to the control mechanism, and are commonly actuated by a spring loaded diaphragm or piston reacting to changes in the feedback pressure to control the valve opening, and in both cases the valve should be opened only enough to maintain the set regulated pressure. The actual mechanism may be very similar in all respects except the placing of the feedback pressure tap.

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  1. Findustry Corp

    Low Viscosity Oil, Tanks, Pressure Relief Valves and Check Valves

    Hi Whoever, I have an idea for a system which would work for my food business but it doesn't exist. The system essentially relies on hydraulics, pressure relief valves and check valves for recirculation upon reached pressure. All tanks/pipes (The entire system) will be prefilled except for 1...
  2. G

    Volumetric flow rate of nitrogen through relieving pressure regulator

    Hello all, I'm having trouble figuring out the volumetric flow rate upstream of a relieving pressure regulator used on a 1/4" OD nitrogen line. Upstream of the regulator P=100 PSIG and T=70F, while downstream P=80 PSIG and T=70F with downstream consumption at q=4 L/min or 0.91 SCFM (at std...
  3. N

    Gas pressure regulator model in Simscape

    Hello, I want to develop a pressure regulator model in simscape. The model will be the springloaded direct acting system and the aim is to target outlet pressure, temperature and flow rate by giving input parameters as pressure, temperature, spring stiffness, length and preload, lever(it is...
  4. caterina magro

    Automotive How to model a CNG pressure regulator?

    I need a help with 1D simulation of a CNG pressure regulator. I have to model this valve in a software called GT power/GT suite. The model has a inlet, ball poppet, piston with spring, outlet and a pipe for balancing the valve. Maybe someone who has experience about modeling this kind of...
  5. A

    Mass Flow Rate of Pressure Regulator

    Hey, I have an air tank that is at a set pressure, say 3000psi, and I have attached a regulator to the end that regulates the pressure down to 800psi. As the valve on the tank is opened the pressure and the mass in the container will decrease. If there was no regulator the mass flow rate would...
  6. D

    Confusion about pressure drops and pressure regulators

    When designing the fuel plumbing for an efi system, do pressure drops in the fuel lines need to be considered when there is a pressure regulator? If so why? Been reading up a lot on plumbing design lately about how the goal is to minimize restrictions in the lines which ultimately cause...
  7. MrBear

    How can I analyze the effects of this orifice in a pressure regulator?

    Hi folks, Firstly a little background, I work for a company that manufactures gas pressure regulators. Last year I was a machinist studying for my HNC in manufacturing engineering. Since passing work has given me the opportunity to work in the product engineering office as a product tester and...
  8. Rob243

    Why Pressure Reducing Valve doesn't prevent backflow

    I am scratching my head on this question. PRV is supposed to create a closed system requiring a thermal expansion tank. But at the same time PRV is not considered a backflow preventer. How can both be true?
  9. Suresh Gadekar

    Choked Flow in 1/4" Pressure Regulator at 3.5bar

    Is it possible to have choked flow in a 1/4" diameter pressure regulator with pressure difference of 3.5bar?
  10. Suresh Gadekar

    Air Pressure Regulator velocity

    I have a pressure regulator that has working the range of outlet pressure 0 to 2 bar, inlet pressure 5 bar, flow rate of 600lit/min and the regulator has 1/4" outlet port (6.35mm). whole data is according to manual I have not tested the regulator. But for flow rate of 600lit/min the velocity...
  11. Suresh Gadekar

    Does a Pressure Regulator Maintain Equal Flow Rates at Inlet and Outlet?

    Is flow rate at inlet of pressure regulator ( not relief valve) equal to flow rate at outlet ?
  12. T

    Pressure regulator question - Concerning flow rates

    I see that pressure regulator curves show different flow rates, but I am confused by this because I was under the impression that the flow rate would be an "output" of the force/pressure balance across the pressure regulator. For example, assuming the inlet to a regulator is 500 kPa, and the...
  13. S

    Pressure regulator model: how to study its stability

    Hi all, I need a model of a pneumatic pressure regulator. The model should be as simplest as possible and use an optimization solver to identify the regulator parameters in order to fit the performance I find in the datasheet of a commercial pressure regulator. I have already done a model...
  14. steves1080

    Why is my pressure regulator drifting down?

    I have a self-venting single-stage pressure-reducing regulator that takes ~2500 psig and steps it down to ~1500 psig (here is a link with the specific details of the hardware if interested: http://www.items.se/Dokument/44-1300_10061107.PDF). I experienced some odd behavior recently where the...
  15. S

    Understanding Pressure Regulators for Gas Cylinders | Expert Help

    Hi, I wanted to know if pressure regulators connected to gas cylinders provide constant outlet pressure, or provide constant pressure drop. Example of the regulator that might be used is this. http://secure.emiratesgas.com/eCom/details.asp?ProductID=ART01661_PR For instance, I have a...
  16. Y

    Pressure regulator affect flow rate through pipe?

    Good day to all, was wondering how a pressure regulator doownstream will affect the flow rate of compressed air through a pipe. Anyone has any insights on this? the pressure regulator is to reduce the downstream pressure but I'm really confused how the flow will be affected. For instance, will...
  17. S

    Does a pressure regulator maintain constant pressure drop?

    I wanted to know the function of a pressure regulator.. Am using one to control liquid flow rate. Here is my understanding- A pressure regulator can be connected across a valve. The pressure regulator maintains a constant "pressure drop" across the valve so if i set it to give a drop...
  18. steves1080

    Mass transfer with with a pressure regulator

    Hi all, I am trying to determine what approach to use to solve the following scenario: I have a pressure vessel with pressure P1 and volume V1. I have another vessel of pressure P2 and volume V2. Vessel #1 is supposed to be a high-pressure storage vessel and vessel #2 is supposed to be...
  19. P

    Special Pressure Regulator Needed

    I am currently working on a project involving a diesel/lime slurry. Problem I am having is that the line that the slurry is coming off of is about 100 psi and it needs to be regulated to about 40 psi. The pressure regulators I have been looking at are not ideal because of the small spaces within...
  20. J

    Pressure Regulator functions and problems

    I have recently been experimenting with pressure to generate a mass flow and discovered something really bewildering. First let me explain the procedure. I use large stainless steel tanks filled to about 3/4 with water so there is a large enough capacity. I then pressurize the system with...
  21. R

    Difference between a flow regulator and a pressure regulator?

    So far I've seen that a pressure regulator regulates the pressure from upstream to required pressure downstream and that a flow regulator regulates the flowrate, obviously. But, theoretically, doesn't one regulate the pressure to induce a specific flowrate? what is the actual difference...