Search for hydrotest requirements in Saudi Arabia and you will mostly find copies of standards documents. They are essential, but they are long and hard to plan from. This article explains, in plain language, what usually shapes a hydrotest on a Saudi project. It is a guide, not a substitute for the documents: always work from the current revisions your client specifies.
The documents that set the rules
Design codes
The test pressure and basic method come from the design code of the equipment:
- ASME B31.3 for process piping in plants.
- ASME B31.4 for liquid pipelines.
- ASME B31.8 for gas pipelines.
- ASME Section VIII for pressure vessels.
Our article on hydrotest pressure and hold time explains how each code sets the numbers.
Owner standards
Large owners add their own requirements on top of the codes. For Saudi Aramco projects, the main documents include:
- SAES-A-004, which sets the company’s general requirements for pressure testing: when testing is needed, test pressure rules, test packages, equipment, inspection and records.
- SAES-A-007, which covers hydrostatic test fluids and lay-up: water quality, chemical treatment and how long water may stay in the system.
- GI 2.102, a General Instruction on carrying out pressure tests safely.
Other owners, such as SABIC affiliates, the Royal Commission industrial cities and utility companies, have their own specifications. The contract will tell you which apply.
What a typical test involves
1. Test package
Each test is planned as a test package, usually containing:
- marked-up drawings (often isometrics) showing the test boundary;
- a test limits diagram with vents, drains, test points and blinds;
- line list with design pressure and temperature;
- calculated test pressure;
- list of items excluded or isolated (instruments, relief valves, expansion joints);
- calibration certificates for gauges and recorders.
The package is reviewed and approved before the test, and the owner’s inspector usually witnesses the test.
2. Preparation
- Remove or isolate items that cannot take the test pressure.
- Install test blinds of the right rating.
- Fit vents at high points and drains at low points.
- Install calibrated gauges and, where required, a pressure chart recorder.
- Install a relief valve on the test system set to protect against over-pressure.
3. Filling
Fill from the low point, venting air from high points. Trapped air is dangerous (it stores energy) and makes the pressure unstable.
4. Pressurising and holding
Raise pressure in steps, checking for leaks at each step. At test pressure, hold for the required time, then reduce to a lower pressure for a visual inspection of all joints and welds if the procedure calls for it.
5. Depressurising and draining
Release pressure slowly and in a controlled way. Drain to an approved location. Open high-point vents while draining so the system does not go under vacuum.
6. Records
The final record normally includes the chart or readings, gauge numbers and calibration, test pressure and duration, ambient and metal temperature, and signatures from the contractor and the inspector.
Test water
Test water quality matters because water left in carbon steel will start corrosion quickly, especially in Saudi heat. Owner standards set:
- acceptable water sources and quality;
- when corrosion inhibitors, oxygen scavengers or biocides are needed;
- how long the water may stay in the system;
- how the system is drained, dried and laid up afterwards.
For stainless steel systems, chloride content in the water is tightly limited to avoid stress corrosion cracking.
Safety
Hydrotest is safer than pneumatic testing because water stores much less energy than gas, but it is still a high-pressure activity. Usual controls include barriers and exclusion zones, a single person in control of pressurising, no work on the system while it is above a set pressure, and checks on the metal temperature to avoid brittle fracture.
Frequently asked questions
Does every new line need a hydrotest?
Most new piping and pressure equipment is pressure tested. A few cases allow alternatives, such as pneumatic tests or in-service leak tests, but only as the code and the owner allow.
Who witnesses the test?
Usually the owner’s inspection representative, along with the contractor’s QC inspector.
What if the test fails?
Find the leak, depressurise, repair, and re-test. See hydrotest failure causes.
Our hydrotest services include test packages, pumps, calibrated instruments and records in Al Jubail, Dhahran, Jeddah and across the Kingdom. Contact us.
