Pre-Gauging Test

Описание: Que - What is Gauging Test in Pipeline?
Ans - Gauging is perform to inspect the internal of Pipeline. Gauging is perform for the section which is Lowered through HDD method.
Four Cup Pigs will be passed to remove mud, dirt, debris and any other extraneous materials.

Rejection - A deformed ,bent or severely damaged pig(Aluminum alloy gauge plate) is evidence of gauging pig run failure and it is not acceptable.

if pig test got rejected then we rectify the section as possible, pass the four cup pig with aluminum alloy gauge plate until we get satisfactory result.

Que - what we have to do if Pig is stuck in pipeline section?
Ans - If pig is stuck in pipeline section then another pig is pass through the section with tracking arrangement in pig so that track the location then after cut the pipeline section and rectify it until four cup pig passed successfully through the section.

Que- What is Gauge Plate used in Gauging?
Ans- Gauge Plate is made of Aluminum alloy with 10 mm thick.

Que- How many types of Gauging?
Ans- Gauging is of two type - 1. Pre-Gauging (Before Pre - Hydrotest above Ground)
2. Post Gauging(After HDD hydrotest performed then Post Gauging)


Que- Where HDD method used?
Ans- HDD method is used for the section where Railways, Road Ways(NH ,SH), Pond and River .


Gauge Plate (Aluminum Alloy - 10 mm thick) diameter is 95% of ID of Pipe.
if we have 12.75 inch (323.85 mm) OD of pipe
and Thickness is 9.53mm then
ID of pipe = OD - Thickness = 323.85 - 2 * thickness
= 323.85 - 2 * 9.53 = 304.79 mm
=
Diameter of Gauge Plate = 304.79*95%
= 289.55 mm