Hydro testing of Seamless Pipes using Paperless Recorders – KD8

This image has an empty alt attribute; its file name is image-6.png
Paperless Recorders


Pipes used for carrying fluids like fuels, fertilizers, gas, etc generally have welded joints.  Welding of joints decreases the mechanical durability of pipes. To mitigate this, industries now use seamless pipes having uniform structure and strength because these do not have  welded joints; increasing pressure withstand capability, ability to work in higher temperature zones and corrosive atmospheres. 

Seamless pipes find applications in nuclear plants, oil & gas industries, boiler manufacturing industries, etc.

As these pipes are applied in critical applications like boiler manufacturing or nuclear plants,  compromise in quality and mechanical endurance cannot be tolerated. Hence, are tested using methods like hydrostatic and eddy current testing.

The hydrostatic testing method ensures that the pipe material is dense and continuous without any leakages.

Problem Statement

Manufacturing of seamless pipes goes through various processes as listed below:

  • Process route for Hot Finished Products
  • Process route for Cold Finished Products
  • Process Route for Casing and Tubing

It was necessary to monitor water pressure through the pipes for a duration of 5 to 6 secs in order to ensure proper cooling of pipes and removal of residual substances left inside the pipes during manufacturing process. 

This helps in detecting the leakage of the pipes formed during the manufacturing process.

The major challenge is to sense input for short duration and scale it to corresponding value of pressure as well as record the same. 


Paperless recorders can fulfill the above mentioned application by providing  data monitoring as well as recording of test parameters. Hence, KD8 a paperless recorder was chosen implementing the following procedure:

  • Using a pressure transducer the input 4… 20 mA DC was applied to the KD8 recorder. The recorder input 4…20 mA was been scaled to the applied pressure of 0 … 10 PSI.
  • The pressure applied would remain for 5 seconds as per procedure (prolonged for 6 to 7 seconds) assuming the application throughout the seamless pipe. The data recorded was taken to PC and analyzed further through respective software. 
Application process
  • From the data captured, graphical representation of data values was created and below points were observed:
    • Pressure application start time
    • Sustain time for minimum 5 seconds to check if the pipe has passed the test
    • Pressure application end time
  • The readings of data can also be recorded in *.csv format which acts as a generated test report and is saved in compact flash card.
  • The data is sampled as per requirement of end customer viz. A customer requires the test report with 20 test points within 6 seconds then the setting done in the recorder is to sample the data every 300 milli-seconds (minimum sampling frequency is 100 milli-seconds).

Other Applications

On the same note, that is for similar applications of hydrostatic testing of seamless pipes, the above solution can find applications in Chemical/Fertilizer industries, Steel manufacturing, Pharmaceuticals and Paper industries.


  • Inputs can be scaled to user-defined output
  • Easy programming and user-friendly interface 
  • Data recording and accessibility in downloadable format
  • User-settable data sampling rate
  • Cost-effective solution

Available features

  • Intuitive servicing – LCD TFT 5.7’’ screen, with touch panel
  • Data archiving on CompactFlash card, capacity up to 4 GB
  • IP65 protection grade on the front panel
  • 3/6 analog programmable inputs and 6/12 alarms outputs
  • Visualization of measurements in digital form, analog indicators, diagrams, bar graphs
  • RS-485 and USB serial interfaces.