pressure relief valve
Pressure relief valves (PRVs) automatically convert high inlet and variable inlet pressure to low and constant outlet pressure.
If there is no water consumption in the network after the breaker valve, the breaker valve automatically shuts off the flow to prevent static pressure from accumulating.
The use of these valves facilitates the operation of the network and transmission lines, eliminates the huge costs of land acquisition and construction of pressure relief tanks, and also reduces fluid unwanted pressure in networks and transmission lines to prevent a large amount of fluid loss.
Select stainless steel pressure relief valve
The first step in choosing a valve is to be careful where you use the milk and know how to use the fluid
In small loads that do not require much precision, the best choice is a pressure relief valve with direct operation
In more uses and for very precise control, pilot-type pressure relief valves can be the best choice
The measurement of fluid pressure reducing valves is easily done by having the passage rate of the passing fluid as well as the inlet and outlet pressure of the valve by the existing tables for selecting the type of valves
Choosing a size larger than necessary for the valves, in addition to increasing the cost of buying milk, will cause the milk to wear faster, because in low loads, the milk will have to work in a close position and due to the small distance between the plug and the seat, the speed in This increased part will cause the inner parts to be eaten and thinned
In addition, a very small movement in the valve will cause large changes in the flow rate of the fluid will cause changes in pressure at the outlet
Problems with pressure relief valves
Since most of the problems of pressure breakers are caused by the entry of foreign objects (in the steam system of wet steam entry), it is necessary to use a strainer (separator in the steam system) before the pressure breaker valves and strainers periodically. And be cleaned and serviced on schedule
If the equipment installed at the outlet of the pressure relief valves is not able to withstand the inlet pressure to the valve, safety valves should be used to protect the device in case of failure
Types of pressure relief valves
Direct acting Pressure Reducing Valve
They are one of the simplest pressure relief valves. The way it works is that the steam pressure coming out of the valve (reduced pressure) exerts a force on the lower part of the diaphragm and in contrast, the spring exerts a downward force in the opposite direction.
The force resulting from the algebraic sum of the above two forces, as well as the upward force on the main valve by the inlet flow to the valve, will determine the exact position of the main valve and thus the percentage of pressure reduction.
The spring power can be adjusted by screwing on the pressure breaker , and as a result, the desired amount of pressure reduction can be achieved by using it and the pressure gauges installed in the steam line.
Pilot Operated Pressure Reducing Valves
These types of valves are used in cases where precise pressure control or high vapor permeability is required.
Their main structure includes adjusting spring, auxiliary diaphragm, guide valve, main valve and main diaphragm.
Pilot valves have advantages over direct pressure valves.
In order to change the position of the main valve, only a very small flow of steam is required, and therefore very low downstream pressure changes cause large changes in the main flow rate, which indicates the high sensitivity of the valve.
On the other hand, the outlets of these valves are independent of the upstream pressure changes, so that although the upstream pressure increases, the vertical force on the valve increases.
But on the other hand, the same force enters the main diaphragm through the pipe, which is neutralized together, and as a result, we will have a valve that will provide precise pressure control independent of the inlet pressure changes.
The interesting point is that if the consumers do not consume steam, the steam pressure from these valves will continue to decrease as much as desired.
Reduce pressure by closing the steel breaker valve in series
In this method, pressure reduction is done in several steps, which is used to reduce pressure in high pressure drops
Reducing pressure by two valves is recommended when the initial pressure is 200 psi or more or the pressure reduction ratio is 1 to 4, for example, reducing the pressure from 250 psi to 50 psi. We use that the valves are not under much pressure difference and as a result the life of the valves is longer.
Reduce pressure by closing the steel breaker valve in parallel
Parallel system (parallel closing of pressure breakers) We provide the pressure drop we want with two or more pressure breakers by dividing the pressure drop between the pressure relief valves
Or we use two pressure breakers in parallel in the system, when one of them leaves the system, the other enters the system and there is no interruption
Or in situations where to supply water to a multi-storey building that requires a certain amount of pressure drop for each floor, we use a parallel system to place the breakers in the transmission path
Rose Calibration Company in Melbourne, Australia with over ten years of experience provides all calibration, maintenance, and repair services throughout Australia. If you live in Sydney, Melbourne, Adelaide, Perth, Geelong, and Brisbane, you can receive your quote in less than two hours by fill-up the form via the “Booking” link.