HYDROTEST [PART - 1]

HYDROTEST

PART 1

Those who are in piping construction will be familiar with the activity called hydrotest. Hydrotest engineers/Supervisors, hydrotest coordinators are some of the posts available for engineers/supervisors in hydrotest activity.

What is hydrotest?

Fill the pipe with water, pressure it and inspect for pressure change and release water. Hydrotest is over. Hydrotest uses water as the test medium.

Is it that simple?

Those who are in hydro testing activity will say a big 'NO'. There are many pre-activities, preparation activities, and post activities for a hydrotest. Moreover, it is also governed by many code rules and good engineering practices.

Hydrostatic Pressure Test

This is the exact technical terminology for hydrotest activity. This is Pressure change leak test when we refer ASME BPVC Sec V. The hydrotest is coming under the category of pressure test. The other one under the heading of pressure test is 'pneumatic test' where the air is used as the test medium.

What are the pre-activities for a hydrotest?

The first activity for doing the hydrotest, is the identification of the pipe system, of which the hydrotest to be done.

All the pipe systems will be parted to small piping lengths called piping loops. For each piping loop, a document (file) is generated (Piping loop file is a topic that needs more detailing and is not discussed here). Each piping loop is checked for mechanical completion and then for NDE completion by respective engineers. After clearance from those two activities, the document is handed over to hydrotest department.

Hydrotest engineer/supervisor will check the document for 'clearance for hydrotest' approval.

From the loop file (the normal site terminology for a piping loop document) the pipe along with its hydrotest limits are identified.

In the identified piping loop, the high point location and low point location will be noted. The basic logic is water will be filled from the low point and vented from the high point.

Safety precautions and access for all flange joints and valves are to be made as part of pre-activity to hydrotest.

Will be continued....