Reasons why a plunger pump does not deliver fluid

It could be a leak in the inlet or outlet valve

The diaphragm is damaged, and the valve assembly in the plunger pump is damaged, resulting in poor sealing and an inability to draw fluid. Leakage in the intake pipeline, poor sealing, etc.

1. Check whether the safety valve at the pump outlet is leaking. Haichuan Chemical Industry Forum http://bbs.hcbbs.com 2. It is necessary to ensure that there are no leaks in the pump body. This article is from: Haichuan http://bbs.hcbbs.com 3. Check whether the check valve at the pump outlet is leaking internally, and clean it if necessary. 4. Check whether the pump inlet is blocked. 5. Check whether the excessively high temperature of the imported materials is causing gas entrapment.

The most important reason is the inlet and outlet valve assemblies. Pay special attention to checking the sealing condition between the valve ball and the valve seat.

Possible causes: 1. Leakage in the inlet and outlet valves; 2. Leakage at the piston packing; 3. Leakage in the outlet safety valve; 4. Clogging of the inlet filter; 5. Leak in the outlet pipeline; 6. Low liquid level in the dosing tank

Check the outlet check valve and the inlet check valve; it’s very likely to be the check valves causing the problem.

Mainly check the inlet and outlet check valves; if there is a filter at the inlet, inspect the filter element.

First, check the inlet and outlet check valves (to see if they are installed in the wrong direction or if they are clogged), then check whether the pump is set too low, and finally inspect the filter and the liquid level at the inlet! !

The manifestations of plunger pump failures include the following: 1. Causes of excessive noise during plunger pump operation and methods to address them (1) Air present in the oil pump. This fault usually occurs when a new pump is installed. When starting a new pump, oil should first be added to it to lubricate the pump’s bearings, plunger, and cylinder barrel. Solution: Open the oil pump filling port while the pump is running to allow the air inside the pump to be released through the filling port. 　　(2) The oil level in the tank is too low; a clogged suction pipe increases the resistance to oil absorption, resulting in the pump drawing in air, or there is a leak in the oil inlet section, causing the pump to draw in air. 　　Solution: Add the required amount of fluid as specified ； Clean the filter and clear the intake ducts ； Check and tighten the connection screws of the oil inlet pipe section. 　　(3) The oil pump and motor are not installed properly; in other words, the coaxiality between the pump shaft and the motor shaft is incorrect, which causes radial forces on the oil pump bearings and results in noise. 　　Solution: Check and adjust the concentricity of the oil pump and motor installation. 　　(4) Excessively high viscosity of the hydraulic oil reduces the pump’s self-priming capacity and lowers its volumetric efficiency. 　　Solution: Use hydraulic oil with an appropriate viscosity; if the oil temperature is too low, turn on the heater. 　　II. Reasons for unstable gauge pointer operation in axial piston pumps and methods to address them （1）Severe wear between the oil distribution plate and the cylinder block, or between the piston and the cylinder block, resulting in excessive internal and external leakage. Solution: Check and repair the mating surface between the oil distribution plate and the cylinder block ； Single-cylinder fitting, replace the plunger ； Tighten the screws at all connections to eliminate leaks. 　　(2) In the case of an axial piston variable pump, it may be due to an excessively small variation angle of the variable mechanism, resulting in low flow rate and a relatively increased internal leakage. Therefore, continuous fuel supply cannot be allowed, as it would cause unstable pressure. Solution: Appropriately increase the variable angle of the variable mechanism and eliminate internal leakage. 　　(3) A clogged oil inlet pipe, increased suction resistance, and air leakage can all cause the pressure gauge pointer to be unstable. Solution: If the oil inlet pipe is blocked and there is high fluid flow resistance, the oil pipeline can be cleared and the inlet filter washed; check and tighten the connection screws of the oil inlet section to eliminate air leaks. 　　III. Causes of insufficient flow in axial piston pumps and methods to resolve them 　This is manifested as slow operation of the actuating element and an inability to achieve sufficient pressure. (1) Low fuel level in the tank, clogged fuel lines or filters with excessive resistance, as well as air leaks, etc. Solution: Check the oil level in the tank. Add it when there is a shortage. Clogged oil pipes and filters should be cleared and cleaned. Check and tighten the screws at all connections to eliminate air leaks. (2) The oil pump was not filled with oil before operation, leaving air inside. Solution: Fill the oil pump’s return port with oil to remove the air inside the pump. (3) The center spring of the oil pump is broken, preventing the plunger from returning; moreover, the sealing between the cylinder body and the oil distribution plate is poor. Solution: The spring at the center of the oil pump lacks sufficient elasticity or is broken. (4) Improper connection of the oil pump causes axial force on the pump bearings, resulting in gaps between the cylinder block and the oil distribution plate, and allowing communication between the high-pressure and low-pressure oil chambers. Solution: Change the connection method to eliminate axial force. (5) If it is a variable axial piston pump, the variable angle might be too small. Solution: If the variable angle of the variable axial piston pump is too small, it should be increased appropriately. (6) Unclean hydraulic oil, as well as wear between the cylinder block and the distribution plate or between the cylinder block and the plunger, cause excessive oil leakage. Solution: Check the wear of the cylinder block, oil distribution plate, and plunger; repair or replace them as necessary, and replace the plunger if needed. (7) If the oil temperature is too low, the viscosity of the oil decreases, which leads to increased internal leakage in the pump; the pump also exhibits symptoms of overheating. Solution: Select hydraulic oil with the appropriate viscosity based on the temperature rise of the oil pump. Identify the reasons for excessively high or low oil temperature and address them promptly. IV. Causes of severe oil leakage in axial piston pumps and methods to resolve it (1) Poor sealing at the various joints of the oil pump, such as damaged seals. Solution: Check the seals at all joints of the oil pump and replace the sealing rings. (2) Excessive wear between the oil distribution plate and the cylinder block, or between the plunger and the cylinder bore, leads to increased external leakage from the return oil pipe; it can also cause internal leakage between the oil pump and its low-pressure chamber. Solution: Grind the contact surface between the oil pan and the cylinder block ； Machine the cylinder block and plunger assembly. Based on experience, pump failures are generally caused by dirty system oil, which leads to damage to the pump; the entry of air into the pump is also one of the factors that reduce its service life. Proper maintenance of the oil is necessary.

The two-plunger pump we use to handle propane is no longer delivering the required flow rate, and we still haven’t been able to figure out why; it’s really worrying. . . . . .