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Introduction DH Series Digital Portable Hydraulic Testers have been designed for easy connection to a hydraulic circuit so that flow, pressure and temperature can be readily checked. Engineering units are factory preset. Testers can take full back pressure up to 350/420 bar (depending on model) and the built-in loading (optional on DHC) valve enables many of the operating conditions to be simulated.
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TROUBLE SHOOTING WITH THE HYDRAULIC TESTER PRELIMINARY:Check oil level in tank, pump drive, valve linkage for damaged parts, external oil leaks etc Problem Possible Cause Suggested Test, See Paragraph: Excessive pump noise Pump cavitation caused by: fluctuating pressure a) Clogged suction filter 3.0;...
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Operation MODELS: DHT and DHC Temperature The thermistor type temperature transducer is in contact with the oil flow and temperature is displayed on the left hand side of the digital display. The factory preset units are indicated by a cursor arrow. Flow Flow Meter The Flow Meter comprises an axial turbine mounted in an aluminium block.
Instructions for using the portable hydraulic tester models - DHT & DHC 0.0 The Tester is designed to measure flow, pressure and temperature. It can take full system pressure up to 420 bar (depending on model) and measure flow in both directions for motor and cylinder testing.
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Keep a record of flow readings at various operating pressures for comparison of test results. The machine Manufacturer’s service manual should be consulted. Cylinder Directional Valve Relief Valve Pump Test Hose Drawing A1 3.0 Test 1 - PUMP IN LINE TEST (See Test Diagram A1) using DHT or DHC Install the Tester into the system between the pump outlet port and the inlet to the directional control valve.
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Cylinder Test Hose Relief Valve OVERALL SYSTEM “TEE” TEST Hydratest DHC Pump Tee Connection Drawing A2 4.0 TEST B - ‘TEE’ TEST (See Drawing A2) using DHT or DHC A ‘Tee’ must be installed at one point between the pump and control valve then connected to the “IN”...
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Control Valve. Cylinder ‘TEE’ Test 4.31 Put control valve in power position. (On multiple spool valves, only one spool should be in a power position at any one time). The cylinder should be extended to the end of the stroke. 4.32 Close tester loading valve slowly while recording pressures and flow rate.
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Cylinder Test (See Drawing B.1) 5.11 If the cylinder is slow in operation or cylinder ‘creeps’ under load the following test should be carried out to check the cylinder seals. Install the flow meter ‘in line’ as shown in Drawing B.1. Actuate cylinder to raise and lower the load.
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Cylinder Motor Relief Valve Directional Valve Relief Valve Test Hose Pump Drawing B2...
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WARNING: Care should be taken while removing the turbine assembly. Damage to the bearing will cause a loss of accuracy and the tester could malfunction. For recalibration contact Webtec Products Ltd or your local sales office.
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LOADING VALVE DHC TESTERS WITH HV100 LOADING VALVE If the handle becomes difficult to turn under pressure or will not close, remove the handle assembly with a 7/8“ AF spanner. Check for worn valve spindle and seat, damaged seals or contamination.
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LOADING VALVE DHT401 TESTERS If the loading valve becomes difficult to turn under pressure or will not close, remove the 4 socket screws. Check for worn valve seat, damaged or leaking seals and contamination. Note: If the pressure does not increase progressively when the loading valve is operated, check if the safety discs have been ruptured.
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LOADING VALVE DHT 751 & 751 HP TESTERS If the loading valve becomes difficult to turn under pressure or will not close, remove the 4 bolts. Check for worn valve seat, damaged or leaking seals and contamination. Note: If the pressure does not increase progressively when the loading valve is operated, check if the safety discs have been ruptured.
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