If the first mile checks out all right, close the gate valve at the end of the second mile of the test section
and open the gate valve at the end of the first mile.
Pressurize the first 2 miles of pipeline.
Patrol for leaks in the second mile.
If there are leaks: close the gate valve at the end of the first mile of pipeline to prevent loss of air
pressure, open the gate valve at the end of the second mile to relieve pressure in the section to be
repaired, repair leaks, close the gate valve at the end of the second mile, open the gate valve at the end
of the first mile, pressurize the first 2 miles of the pipeline, and patrol again to look and listen for leaks.
Repeat the above steps until the 5-mile section of pipeline has be tested and all leaks repaired.
Pressurize the whole 5-mile section for a 24-hour test if there is enough time.
Anchor the end of the pipeline after the test is over or hold it down with heavy equipment so that it
cannot whip around. Warn everyone in the area to stand clear of the line. Then empty the air from the
line by opening the gate valve at the end of the test section. Open the gate valve as quickly as possible.
Preparations for Testing. Before the test is begun, several actions should be taken. To ensure that
the test runs smoothly:
Test all radios and telephones.
Check the accuracy of all gages.
Make sure enough repair clamps are on hand.
Move in fire fighting equipment.
Make sure a tank vehicle and drums are nearby in case a section of line has to be drained.
See that shovels and material to dig and line a pipe are at the test site in case there is a spill.
The pipeline should be divided into test sections. The usual test length is the distance between pump
stations (about 15 miles). Shorter distances can be tested by using gate valves to divide the pipeline into
smaller segments.
During testing, line pressure in welded pipelines is measured by gages at pump stations and at line taps
between pump stations. Before the test is begun, over-coupling leak clamps with pressure gages are
mounted on coupled pipelines to measure line pressure. The clamps are mounted every one-third mile, if
practical. If not, they are used at least every mile. To mount an over-coupling leak clamp for a pressure
test:
Remove the vent plug and put a pressure gage in the vent plug hole.
Loosen the split ring coupling on the pipeline.
Remove the gasket or push a nail under the gasket to make a small leak. (The nail should not damage
the gasket and should not get in the way of the over-coupling leak clamp.)
Remove nuts and bolts from the over coupling leak clamp.
Fit the two halves of the leak clamp and the two part gaskets over and around the split ring coupling.
Put the large side bolts back in on each side of the clamp and tighten them.
Tighten smaller packing bolts around the housing on the leak clamp to form seal between the gaskets
and the pipe.
PART C - PIPELINE PATROLLING
When put into service, pipelines are patrolled by at least two people. The patrols look for leaks and signs of
a leak such as an oil slick on a stream and/or dead or wilted plant life nearby. They report all leaks on a DA
Form 5464-R (Petroleum Products Pipeline Leakage Report). Patrols also prevent or hinder sabotage or
theft. They are sent out often and at different times each day so that no one can predict when a patrol may
be in a specific area. Usually, patrols are not sent out during the night because leaks are hard to spot when
flashlights must be used. Patrols can be made on foot, by using a jeep or truck, or by using a small airplane
or helicopter.
Foot and Motor Patrols. Foot and motor patrols are equipped with radios or telephones, coupling
wrenches, grease, gaskets, and repair clamps to make minor on the spot repairs. Motor patrols can carry
more equipment and cover more territory than foot patrols, but they are limited to areas where the pipelines
run alongside a road. Foot and motor patrols report major leaks to the pump operator as soon as possible.
8-4
QM 5096
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