Instructions for Laying

FSR 8.70.05

FLEXWELL Safety Pipe

Instructions for laying and mounting FLEXWELL Safety piping

FSR DN 12 – DN 150

Pressure test of the inner carrier pipe after completion

of laying

Attention:

Do not carry out a pressure test with liquid.

Pressurize the inner pipe/outer pipe slowly. It takes some

time after beginning the filling for the pressure to build up.

It rises rapidly just before it reaches the desired pressure.

Remember to give the system time to stabilize. Then bring

it up to the desired pressure in small steps.

Test pressure for the inner pipe:

The maximum allowable pressure PS for the inner pipe

is 25 bar. The maximum allowable test pressure is

25 x 1,43 = 35,8 bar.

The test pressure PT shall be the “maximum allowable

pressure of the pipe system” x factor 1,43.

For example: If the maximum allowable pressure of the

system where the pipe is connected to is 6 bar the test

pressure shall be 6 x 1,43 = 8,6 bar.

A pressure test is not necessary if the pipe is only used as

a suction pipe. In that case a leak test as described before

is sufficient.

Pressure test of the outer containment pipe:

The maximum allowable pressure PS for the outer pipes is

25 bar.

The maximum allowable test pressure for the outer pipe is

25 x 1,43 = 35,8 bar.

The test pressure PT shall be the “maximum allowable

pressure of the monitoring system” x factor 1,43.

For example: If the maximum allowable monitoring

pressure is 3 bar the pressure shall be 3 x 1,43 = 4,3 bar.

A pressure test is not necessary if the monitoring pressure

of the outer containment pipe is only in the range between

–0,7 bar to 0 bar. In that case a leak test as described be-

fore is sufficient.

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Find out from the local authorities or inspectors what the

required procedure in their area of jurisdiction is and the

test frequencies. Fill nitrogen or clean, dry compressed air

into the inner pipe.

Attention:

Pressure testing with gas has significant dangers

and require safety precautions. They must comply

with the local legal regulations.

Please note:

This only makes sense when the pipe is protected

from direct sunlight/cold. Measuring errors can

occur due to changes in temperature. This test

should be seen as an additional test, not as the

main leak test.

Warning:

Only carry out this test when the piping is in the

correct position as intended and secured in place

in the shafts, screwed onto the fittings/valves as

envisaged. The piping must be packed around with

stone-free sand.

19.08.2024

KIWA Subject to technical changes.

Page 43

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