Pressure relief valve and safety valve

As you know, the main prerequisite for doing any work is to have correct information about that subject. Regarding selection, checking the prices, buying, and getting to learn more about pressure relief valves and safety valves, the following information is included so that  you, dear visitors of the specialized website of DamaTajhiz, can use these tips to get enough information to choose and buy from Honeywell, Satronic, Setak, Star, Hysk, Pintosi, CS case, etc. brands in bulk.

Guide to choosing and buying pressure relief valves and safety valves

A pressure relief valve is a valve that reduces the inlet fluid pressure and also controls the fluid pressure at the outlet of the valve so that the outlet pressure is lower than the inlet pressure. Pressure relief valves are usually used to control high water pressure in high towers, wide fluid transmission networks, large industrial tanks, etc. They are not used for domestic water piping systems. Join us in introducing and checking the performance of different types of pressure relief valves and safety valves in the rest of this article (for wholesale purchase).

The difference between a pressure relief valve and a safety valve

Most of the time, and by mistake, pressure relief and safety valves are considered one product. If these two valves have two different functions, each one has a different application. Below we mention one of these differences.

When the tank pressure rises above a specific limit, the safety valve opens entirely and releases the pressure at once without the help of the controller.

But when the pressure in the pressure relief valve increases, the controller or actuator operates. When the pressure relief valve disk opens, the excess pressure in the tank is gradually discharged.

Types of pressure relief valves in terms of performance

• The direct pressure relief valve
• The pilot pressure relief valve
• Diaphragm pilot pressure relief valve
• Piston pilot pressure relief valve

Pressure relief valve function in simple language

The force of the water pressure, which is indicated by the green arrow in the picture below, pushes the spring upwards, and the force of the spring, which is indicated by the red arrow, constantly pushes the spring down; as a result of this function, both forces neutralize each other, and the pressure is stable. We will have at the output.

The direct pressure relief valve

With a simple and small structure, this valve is used to control low pressures and directly reduce the pressure.

The pilot pressure relief valve

This valve has a pilot that directly operates the valve and reduces the pressure, and is used to control high pressures. It has two types of piston and diaphragm.

Diaphragm pilot pressure relief valve

This valve has a large diaphragm that is responsible for operating the valve and can minimize pressure drop fluctuations during flow control. This valve can control high flows and can reduce a lot of pressure. This valve is used in industry, large construction projects, wide and high-pressure fluid transmission and distribution networks, air conditioning equipment, irrigation, etc.

Pressure relief valve with piston pilot

This valve has a piston for the operation of the valve and is widely used in steam lines, and has high control ability to reduce pressure with fluctuations of up to 0.05 MPa. This valve is also used in various industries, large construction projects, wide and high-pressure fluid transmission and distribution networks, air conditioning equipment, irrigation, etc., just like diaphragm pilot valves.

Types of pressure relief valves in terms of the working fluid

• hydraulic
• pneumatic

The hydraulic pressure relief valve

This valve regulates the fluid flow in the hydraulic system, which is connected to the valve as a manual lever and is used in industries such as automobile manufacturing, cement, steel, etc.

The pneumatic pressure relief valve

The pressure in this valve is sensed by the sensor and sent to the controller. This milk is used in agriculture, textile, automotive, food, wood, etc.

Advantages of pressure relief valves

• low cost
• Easy maintenance and installation
• simple design
• Reduce leakage
• No need for external force for the operation
• Low friction

Disadvantages of pressure relief valves

• The control environment must be spotless
• Loss of controllability of regulators at low pressure
• Incompatibility of regulators with silence

The steps of installing a pressure relief valve

Before installing the pressure relief valve, open the system valves so that the air in the piping system is completely drained.

To facilitate maintenance, install two shut-off valves on both sides of the pressure relief valve.

Install the valve vertically or horizontally, preferably not upside down.

Close the manual flow shut-off valve in the upper part and twist the upper spring of the pressure relief valve to reach the desired pressure.

To increase the output pressure, turn the spring clockwise, and turn the spring counterclockwise to decrease the output pressure.

What is a safety valve?

Safety valves have a protective function by performing pressure adjustment; that is, when the pressure of the fluid entering them rises above a specific value, they operate automatically, and their valve opens, and by draining the fluid, it brings the pressure to the standard level and avoids risks such as an explosion. They are prevented in closed tanks, and finally, when the pressure reaches a level lower than the maximum pressure of the safety valve used, the valve closes again. The pressure measurement unit is in Bar or PSI, and the safety valves have two ASME or API526 standards.

Among the safety valve applications, we can mention the use in hot water tanks with coils, double-walled engine room sources, fuel storage tanks, boilers, piping systems, pressure tanks, etc.

The safety valve has three types.

• Spring-loaded safety valve: In this type of design, the spring is designed to push the disk against the incoming flow, and when the pressure exceeds a certain level, the spring opens, the disk is released, and the fluid flows into the valve.

• Net weight safety valve: in this type, no spring is used, and with increasing pressure, the disk rises, excess pressure is discharged, and it is used for low-pressure tanks.

• Safety valve with the pilot: This valve consists of two parts: the main and pilot valves. In this model, the pressure is adjusted by the pilot valve, and it is used in high-pressure tanks and large valves, where a higher reliability factor is required.

In the group of pressure relief valves and safety valves of the Damatajhiz reference site, information and prices of all types of pressure relief valves, safety valves, venting valves, etc., from brands such as CS Case, Hysk, Honeywell, etc., with original warranty for review and purchase. It is presented to you, dear users and employers.

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