Hydraulic Pressure Testing Overview

Posted on May 20, 2021

Hydraulic Pressure Testing

The piping system leakage check is normally done by a visual check. The operator will examine all the components of the piping system to see if there is any defect or leakage. The critical spots are the joints, flanges, fittings, and valves. The pressure check is done by the pressure gauges that are mounted to the pressure line.

Hydraulic pressure testing is a process to make sure whether there is an error in a piping system or any defect in the components. The error or defect in a piping system is essentially the leakage of the fluid or the drop of the hydraulic pressure. During the hydraulic pressure testing, the test pressure is usually set to be 1.5 times the normal working pressure. The test is considered passed if the piping system can handle the test pressure over a determined period of time. Hydraulic pressure testing is also called pressure testing or hydrostatic pressure testing.
 

Equipment Required for Hydraulic Pressure Test

A hydraulic pressure testing circuit is needed in a pressure test. The three main components of the testing circuit are the hydraulic power unit, hydraulic power pack, and pressure testing materials. The hydraulic power unit is the agent to drive the fluid in the hydraulic system during the testing process. The main goal of the power unit is to fill the testing fluid into the piping system. The testing fluid is mostly pressure testing oil. The hydraulic power pack is used to boost the pressure in the piping system. The hydraulic power pack is usually portable in size. The testing materials that are used in such tests include gauges, manifold, valves, and blank flanges.
 

Pressure Testing Circuit Setup

In a piping system, there are usually three lines including the drain line, the return line, and the pressure line. These three lines are connected by a tee through the hoses. In a hydraulic pressure testing process, these three lines will be connected separately to the hydraulic power unit through the check valves. As for the hydraulic power pack, it will be connected to the pressure line through a pressure testing manifold solely in order to increase the hydraulic pressure in the pressure line. The manifold has a drain valve and a pressure gauge that is mounted to the end of the pressure line. In a typical hydraulic pressure testing process, there will be a pressure gauge at the source of pressure input and another one at the very end of the line.
 

How Is a Pressure Test done?

The standard procedure to carry out hydraulic pressure testing is as follows. The piping system to be tested will be filled with the testing fluid. The pressure inside the piping system will then be boosted by the hydraulic power pack through the pressure line. The pressure of the pressure line will, later on, be released. At last, the return line, as well as the drain line, will be pressurized to the determined testing pressures respectively. During this process, it is important that the hydraulic power unit fills the piping system with testing fluid in replacement of the regular working fluid.
 

Pressure State inside the Lines

After the piping system is filled with the testing fluid, the drain line and the return line will be isolated with the hydraulic power unit. On the other hand, the hydraulic power pack will be attached to the pressure line to increase the pressure of the piping system. The hydraulic pressure in the pressure line will be increasingly boosted. Among these three lines, the pressure in the pressure line will be the highest during the pressure testing process. The pressure line is also the first line to be tested. When it is in testing, the pressure line is isolated from the return line and the drain line. The pressure test of the return line and drain line is done as the pressure line is tested.

The pressure inside the piping system will be gradually increased until the pressure within reaches the predetermined testing pressure, which is usually set to be one point five times the regular working pressure. The piping system will have to withstand the testing pressure for a given period of time. The time is determined mainly based on the customer’s requirement, but it is usually around fifteen minutes to twenty minutes. Within this period of time, the whole piping system will be checked in making sure if there is any leakage taking place or not. A piping system is proved healthy and intact if no leakage is spotted during the time it is pressurized.
 

Piping System Leakage Check

The piping system leakage check is normally done by a visual check. The operator will examine all the components of the piping system to see if there is any defect or leakage. The critical spots are the joints, flanges, fittings, and valves. In addition to the leakage check, the pressure check is also needed during the test. The pressure check is done by the pressure gauges that are mounted to the pressure line. If the gauge indicates a pressure loss, chances are there is something wrong inside the piping system and procedures will be taken for the further testing process.

If there is no visible fluid leakage as well as pressure loss, the pressure testing is done and the function of the piping system is proved normal. After the test, the pressure will be released through the drain valve, and the return line and drain line will be pressurized through the pressure line by opening the connecting valves. The pressure of the return line and drain line is checked by the gauges at the manifold and the end of the pressure line. At this stage, since all the three lines are connected, the pressure in these three lines should be the same. Once the pressure is checked, the entire process of hydraulic pressure testing is completed.
 

IMTS Exhibition

IMTS gathered worldwide Hydrostatic Pressure Tester manufacturers into this online platform. Browse and search for your next supplier with us.

Should you run into any difficulties, please do not hesitate to contact us.

Quick Link to Suppliers

0Inquiry Item Contact IMTS