MECHANICAL EQUIPMENT FOR INSPECTION AND TESTING

Mechanical Equipment for Site Inspection and Testing During Erection

Water Treatment Plant Major Equipment

The extent of testing during erection should include, but not be limited to, the following.

Checking the accuracy and alignment of plant erection. The accuracy should comply with the relevant standards, the specification or the plant manufacturer’s requirements as may be applicable or where no requirements exist, to a standard to be agreed between the Engineer and the service provider.

Checking the alignment of rotating equipment is to the manufacturer’s requirements.

Non-destructive testing of site welds as required by the relevant standard and as detailed in the specification.

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Types of Test during Erection

The types of test should be carried out in site as per nature of works. Particular for this project the types will be as below:

Hydro-static Test

Hydro-static testing of pipe work systems at a pressure of 1.5 times the design pressure but not less than 4.5 bars for a period of working hours, or at such other conditions as may be required by the pipe work design code.

Hydro-static tests should be carried out on steam generating units in accordance with the boiler design code.

 

Air-Pressure Test

Air piping should be subjected to an air pressure test rather than a hydro-static test.

Vessel Test by Hydro-static

Site fabricated tanks and vessels should be subjected to hydro-static tests in accordance with the relevant standards.

Draining after Test

After the hydro-static test is carried out, the complete assembly should be drained and any non-drain-able sections should be injected with an oxygen-absorbent chemical and elements plugged.

 

Test for Site Fabricated Stuff

Pressure vessels and other parts including pipe work that is made up on site and is subject to pressure or vacuums under normal or abnormal working conditions, should be subjected to a site hydraulic test at approved pressures and for approved periods in accordance with the relevant standard. Where no appropriate standard exist the hydraulic test pressure should not be less than 1.5 times design pressure or at such pressure to be agreed by the Engineer.

 

Alternating Air Pressure Test

Should, in the opinion of the Service provider and with the agreement of the Engineer, an hydraulic test be impracticable due to excessive loading on foundations other than steel, an air pressure test may be employed in accordance with requirements set out in BS 5500.

Vacuum tests should be carried out at the maximum test vacuum obtainable and the condition maintained for a period of two hours with the system isolated. The Service provider should state in the Schedule of Guarantees the fall in vacuum anticipated during this period but the rate of all should not exceed that which would occur due to the designed air leakage rate being attained.

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Calibration checks on all instrumentation.

Tests to be demonstrate the correct functioning of the control loops, protective devices, interlocks and alarms.

To be flushing out of all pipe-work systems which have not been fully cleaned and sealed before shipping to site. Other tests as specified which have not been previously conducted.