Sprinkler pressure reducing valve is a valve that reduces high-pressure medium in the system to low-pressure medium and keeps the downstream pressure stable. Its feature is maintaining the outlet pressure within a certain range despite constantly changing inlet pressure.
Sprinkler pressure reducing valve comes in many types, which can be classified based on working principle into: Direct-acting sprinkler pressure reducing valve, Proportional sprinkler pressure reducing valve, and Pilot-operated sprinkler pressure reducing valve. The commonly used type in irrigation systems is the Pilot-operated sprinkler pressure reducing valve, which consists of two parts: the main valve body and a hydraulic control component (pilot valve, needle valve, conduit).
Its working principle is that when the sprinkler pressure reducing valve main valve body is supplied with water at the inlet end, water flows through the needle valve into the upper chamber of the main valve body. The outlet pressure of the main valve body acts on the pilot valve through a conduit. When the outlet pressure is higher than the spring setting value of the pilot valve, the pilot valve closes, and the upper chamber of the main valve body stops draining. This increases the pressure in the upper chamber of the main valve body, causing the diaphragm (valve plate) to move downward and reduce the flow path of the main valve body, lowering the outlet pressure of the main valve body. When the outlet pressure of the main valve body drops to the pilot valve spring setting pressure, the pilot valve opens, allowing the upper chamber of the main valve body to drain downstream.
Since the drainage from the pilot valve is greater than the inflow of the needle valve, the pressure in the upper chamber of the main valve body decreases, causing the diaphragm (valve plate) to move upward and increase the flow path opening of the main valve body, raising the outlet pressure of the main valve body. A stable state is achieved through the balance of hydraulic action, with the inflow and outflow of the upper chamber of the main valve body being the same and the flow path opening remaining unchanged, thus maintaining the outlet pressure of the main valve body at the set pressure value.
The outlet pressure of the main valve body of the Pilot-operated sprinkler pressure reducing valve is set by adjusting the spring bolt of the pilot valve. With water flowing through the sprinkler pressure reducing valve, turning the adjustment bolt on the top of the pilot valve clockwise increases the outlet pressure, while turning it counterclockwise decreases the outlet pressure.
Adjustment of the pilot valve's adjustment bolt should be done slowly, with each adjustment being 1/2 or 1/4 turns since there is a delay reaction time between the pilot valve action and the main valve body diaphragm. It is suggested to observe after each adjustment and continue increasing or decreasing outlet pressure only after the outlet pressure gauge reading has stabilized. Avoid rapidly increasing the valve outlet pressure when the downstream pipeline is not fully filled with water and the pressure is not yet stabilized.
Observe the outlet pressure gauge changes of the main valve body, and when the desired pressure is reached, lock the nut of the adjustment bolt of the pilot valve. It is recommended to use two wrenches simultaneously during locking—one to fix the adjustment bolt and the other to lock the positioning nut to prevent movement of the adjustment bolt during the locking process.
Sprinkler pressure reducing valve is usually installed in locations that need to maintain stable downstream pressure.
.
The pipeline network should be flushed before installing the sprinkler pressure reducing valve.
sprinkler pressure reducing valve must have its water flow direction in line with the pipeline network water flow direction.
If the water quality is not clean, a filter must be installed upstream of the sprinkler pressure reducing valve.
For ease of operation and maintenance, the sprinkler pressure reducing valve is generally installed upright on a horizontal pipeline.
English
Español
русский
العربية