Troubleshooting of pressure testing machine

Faults and troubleshooting
1. The oil pump does not deliver oil
Cause: The air filter in the oil pump is blocked and does not match the oil outlet valve seat, and the steel ball and ball seat have scratches and burrs.
Troubleshooting: open the high-pressure oil outlet pipe connector of the oil pump to exhaust. Clean and exhaust the air in the oil pump. Replace or repair the corresponding parts.
2. The oil delivery of the oil pump is unstable (the pointer can be seen to stagnate and vibrate).
Cause: oil viscosity is too small (too thin) or too dirty; There is air in the oil circuit. There is dirt or galling between the oil delivery valve piston and its liner. There is oil leakage.
Troubleshooting: replace clean oil with proper viscosity. Remove the air in the oil circuit, raise the piston for a distance, and then open the oil return plug. Clean and grind the roughened parts. Find out the oil leakage and eliminate it.
2. Oil pressure pulsation (the oil return pipe of the oil delivery valve is intermittent, and the pointer of the standard dynamometer shakes during the load indication verification)
Cause: There is air in the oil pump. The oil viscosity is too low (too thin). The throttle needle clearance of the oil delivery valve is too large. There is dirt in the oil pump. The oil outlet valve seat does not match, and the steel ball and ball seat have burrs and scratches.
Troubleshooting: remove air. Change the appropriate fluid. Reduce the clearance of throttle needle. Clean the oil pump. Replace or repair corresponding parts.
3. The oil pressure cannot reach the maximum load
Cause: The oil plug of the oil delivery valve is too tight with its sleeve or there is dirt. The spring force of the oil delivery valve is too small. There is a large oil leak. The front end of the oil delivery valve piston leaks. The oil pipe joint leaks oil. The working piston clearance is too large. The needle port of the return valve does not match.
Exclusion method; Clean or grind corresponding parts. Add a washer on the spring end face or replace the spring. Eliminate oil leakage. Tighten the insert. Replace the washer and tighten it. Slightly increase the oil viscosity or replace the piston. Grind the oil return valve.
5 The pointer does not return to zero after unloading
Cause: The rack is stuck. The swing rod falls back too fast to make the rack jump out of the roller.
Troubleshooting: adjust the spring plate. Re-engage the rack. Rotate the rack to zero.
6. The thallium falls back too fast after the specimen is damaged, resulting in impact.
Cause: oil viscosity is too low (too thin). The clearance between the cone of the buffer valve and the valve port is too large.
Troubleshooting: replace the oil with proper viscosity. Readjust the clearance or correct the buffer valve and nut threads.
7. The drop of thallium is too slow
Cause: The oil viscosity is too high. The clearance between the cone of the buffer valve and the valve port is too small.
Troubleshooting: replace with proper oil. Readjust the clearance.
8. Start the oil pump and the pointer swings back and forth after operation
Cause: (1) The lower end of the force measuring piston is not aligned with the top block.
Troubleshooting: correct the position
9. Indication error out of tolerance
Cause: The friction between the force measuring cylinder and the force measuring piston is too large, which is polluted, rusted and roughened, resulting in negative value. The friction between the working oil cylinder and the working piston is too large, and there is pollution, rust and roughening, resulting in a positive value.
Troubleshooting: cleaning, derusting, grinding (2) Same as above
The indication value of the 10-degree dial is unstable, and the error direction is variable during multiple pressure tests
Cause: (1) The nuts on the upper and lower columns are not tightened. (2) Poor fitting of ball socket.
Troubleshooting: tighten the lapping ball socket.
11. The cement specimen is damaged in one side after compression
Cause: (1) Poor fitting of ball socket
Troubleshooting: (1) Grind the ball socket
12 The crack sound of the test piece is too loud when it is broken
Cause: The cylinder clearance is too large. The piston rises too high.
Troubleshooting: add cushion blocks to reduce the lifting height of the working piston.
13 No printout during automatic control
Cause: No printing paper
Troubleshooting: load printing paper
14 Failure of loading automatic control device
Notify the manufacturer to send professional personnel to repair