Your reciprocating piston compressor will have a smooth start up, thanks to the unloader valve. The air compressor unloader is valve is a small, but important, part of the reciprocating piston compressor. Big unloader valve which is controlled by a small pilot unloading valve.
The air compressor unloader valve provides a critical function in preparing your air compressor to restart. A failed air compressor unloader valve is one of the most common reasons why your air compressor cannot restart after you have used air from the compressor tank. What the unloader valve does is that is responds to the compressor pressure switch turning the power off to the motor and allows any air that may be trapped over the piston, or pistons on a multi-cylinder air compressor, to vent to atmosphere, removing any load that the trapped air may have created over the cylinder piston.
The following blog post will help you understand the piloted unloader valve by pointing out its components, explaining how it works and describing the adjustment process. The diagram below shows the components of our most common piloted unloader valve, part number 131B. How It Works. Piloted unloader valves combine a pilot valve and an unloader valve to run an air compressor continuously.
Gas air compressor unloader valves are one of the numerous small, common and essential parts of an air compressor and the whole pressure maintenance process. The air compressor unloader check valve keeps the entire tank from draining and has a pipe running to the unloader valve. The air evacuating from the unloader valve does not stop the unloader valve from continuing leaking air after the compressor is stopped.
An unloader valve malfunction is one of the more common air compressor issues. If you own a smaller reciprocating air compressor, you’ll likely find the unloader valve mounted on or inside the pressure switch. A larger air compressor often features a more sizeable unloader valve controlled by air pressure emanating from a smaller pilot valve.
This component is responsible for activating engine control, reducing oil consumption by leveling pressure between the check and pump valve, diverting air pressure from the tank when top pressure setting is reached and discharge air pressure automatically when the compressor reaches the maximum pressure setting. The air compressor unloader valve is a very small but crucial part of the whole pressure maintenance process. Adjust the compressor to the minimum load pressure setting and turn the compressor off.
how to check air compressor unloader valve Related Question:
How do you know if your air compressor unloader is bad?
You can have two problems. Air leaking from an “unloader” valve on the pressure switch continuously (after the motor shuts off) is an indication of a leaking tank check valve, not a bad pressure switch. Air leaking from the unloader while the motor is running is an indication of a bad unloader valve.
How does an unloader valve work on air compressor?
While the air compressor is running, the pilot remains closed until the pressure reaches the unload setting. When that happens, the pilot opens and pressurizes the unloader valve, causing the unloader valve to open and excess air from the compressor to vent to atmosphere.
How do I know if my unloader valve is bad?
Water leaks and inconsistent behavior are also signs of a potential failure in the near future. González: The typical signal when there is an unloader malfunction is a reduction of flow through the nozzle, which results in pressure loss. Dean: Typical symptom of an unloader failure is a sudden smooth pressure loss.
How do I know if check valve is bad?
Symptoms of a Failing Check Valve For example, failing check valves will start to vibrate and even lose some internal parts when problems begin to arise. Other symptoms of check valve failure include reverse flow and excessive component wear and damage. Check valves will also emit noises as they start to break down.
Why is my air compressor losing pressure?
Pressure drop can be caused by any obstruction to airflow that might appear across the various components that comprise a compressed air system. If the airflow is restricted due to the presence of gunk in one of the passages, it could lead to a slight loss of air pressure between the unit and end-point application.
Where is the check valve on an air compressor?
Located between the compressor and the air receiver tank or main header, a check valve is designed to prevent air from bleeding out of the tank or header and back into the inlet line when a compressor shuts down. Unloader valves, meanwhile, allow air to bleed out of the compressor line to reduce load on startup.
How does a pressure unloader work?
The pressure-actuated unloader is a simple valve and spring arrangement set in a meal (usually brass) body. A channel drilled through the body gives water access to the back side of the valve ball. When pressure against the valve increases to a point where spring tension is overridden and water is diverted by bypass.
What is the difference between a regular relief valve and an unloading valve?
The relief valve protects the low-volume/high-pressure pump from pressure above 3000 psi. The unloading valve is set at 500 psi to divert flow from the high-volume/low-pressure pump to tank when system pressure climbs above this setting.
How do you adjust a piloted unloader valve?
as tank pressure approaches 135 PSI, slowly turn top end setting (4) counterclockwise until pilot starts to unload prematurely (at 105 PSI). clockwise in 1/4 turn increments, tap down on internal rod at toggle and repeat until desired top end setting is reached.
What does a unloader valve do?
The function of an air compressor unloader valve is to release the remaining air from the compression chamber and relative lines when the motor turns off.
What happens if unloader valve is bad?
A failed unloader valve can cause high pressure at the nozzle. The unloader valve recirculates water to the pump inlet when the pump is running but the spray wand isn’t in use.
Why does my pressure washer dies when trigger released?
If a pressure washer stalls when the trigger is released, this usually indicates a fault in the unloader valve. It is a simple process to remove and replace the unloader.
Can a check valve get clogged?
One, check valves are prone to jamming in the open position, thereby becoming an uncheck valve of sorts. Two, they are prone to jamming in the closed position, preventing water flow in any direction. And three, they can restrict water flow.
When should a check valve be replaced?
Look for signs of corrosion, rust or mineral build-up. Replace the valve if there are extensive leaks or worn/broken pieces. Open & close the valves to make sure they aren’t seizing. Inspect pressure & temperature of fluid flowing through.
How do you test an air pressure switch?
With air applied to the pressure switch, place one lead of the ohm meter to one of the loose wires, and the second lead to the second loose wire. The air pressure switch should close when air is applied. If the switch closes, the ohm meter will read zero ohms, indicating the air pressure switch is good.
