In this post, I would like to bring you an important safety tips. Hydrostatic pressure test safety. This topic is very important because you -as an owner of a project- might not be focus on it. Your contractor will handle it for you.
Hydrostatic pressure test is a common non-destructive test methods used for testing piping and pressure vessel after its construction. This method is often preferable by owner because of product consideration.
What Are Hydrostatic Pressure Test Hazards?
However, in frame of safety, hydrostatic pressure test contains a potential hazard. It can cause injury and fatality as well as property damage if it is not handled properly.
As what has happened to an employee at Energy Product Tubular Division in US. At that incident, the employee died after being struck by plug during hydrostatic test of a pipeline at 1,000 psi. You can read the accident report by OSHA here.
Hydrostatic pressure test uses water in high pressure. The applied pressure is 1.5 times design pressure.
If the design pressure is 10 bar.
So, the applied pressure for hydrostatic test will be 15 bar!
Under such high pressure circumstance, a potential energy inside a pipeline or equipment is ready to damage anything besides it.
So that’s why it is very important to keep hydrostatic pressure test safety.
Hydrostatic Pressure Test Safety Tips
It had better if you make the following safety tips in a form of hydrostatic test safety checklist.
So, anyone can use it as a guideline easily.
- Always follow applicable standard and best practice for hydrostatic test
- Carry out job safety analysis for pressure testing first before you start
- Make sure all workers who involve in hydrostatic pressure test are trained and have adequate skill
- Check the design pressure carefully. Then, calculate the hydrostatic pressure test value. Get approval from the authorized personnel for the test pressure.
- Inspect all equipment you use for the test such as hoses, pressure gauge, piping and temporary closure have higher strength than the test pressure.
- Use only material in good condition. Never use susceptible, brittle or stress corrosion cracking material.
- Ensure that all valves, piping, flanges and vessels that will be tested have a known specification. Cross-check between the document and marking on these materials.
- You can reuse some materials for the hydrostatic test. But, ensure that you have inspected their condition prior to reuse them.
- All piping and equipment support exposed to the test pressure shall have proper strength.
- Prepare pressure relief valve for hydro testing to prevent over pressure. Check the specification and make sure it is in good condition.
- Remaining air inside the piping and equipment is not allowed. It is very dangerous. So, make sure you have already released the air before starting hydrostatic test
- Install safety barrier surround the pressure test area. If necessary install safety line too.
- Use appropriate safety signs to notify people about the hydrostatic pressure test. Install them in a proper location to be visible.
- Wear appropriate personal protective equipment (PPE) during the test
- Only authorized workers can be in the test area
- Only use calibrated pressure gauge with coverage pressure measurement of 1.5 to 2.0 times test pressure. Make sure to check the calibration record.
- Get safety work permit before starting the hydrostatic pressure test
- Announce the pressure test plan to affected area
- You have to stop the hydrostatic test when you find unsafe condition during the test. Do not ignore any unsafe condition since it may trigger an accident.
- Standing in front of pressure gauge during the test is very dangerous. Avoid doing this.
- Prepare enough lighting before the test even though you do the test at an open area.
- Keep a safe distance during the pressure test to minimize safety risk. Refer to a standard for safe distance calculations
- Relief pressure first after hydrostatic pressure test finished prior to draining water from the tested piping or equipment.