Monday, November 23, 2020

Hydro Jetting & Hydro Testing Purpose

The Hydro Test is Conducted to Ensure:

  • Stability
  • Integrity
  • Leak.

Types of Tests Conducted in the Pipeline

There is a test in almost every step. pipelines are referred to with standards like:

  • API,
  • ASME,
  • ASNT,
  • ASTM etc.
  1. Welding - Procedure Qualification (PQ) and Welder Qualification (WQ) - Involves Destructive Testing-DT
  2. Non-Destructive - Radiography, Ultrasonic, Dye penetrant & Magnetic Particle Testing (MPT)
  3. Field Joint Coating (FJC)- Procedure Qualification (PQ) for Heat Shrink Sleeves (HSS) and Certifying manpower for further installations.
  4. Hydrostatic Testing - Pipeline Integrity Test.
  5. There are several tests before Hydrostatic Testing (HT) – for example Cleaning & Gauging.
  6. The tests conducted after hydro test:
  7. Swabbing and Magnetic Cleaning,
  8. Vacuum Drying,
  9. Nitrogen
  10. Purging, Electronic Geometry Pigging (EGP), Recommissioning checks and commissioning
  11. PIG is abbreviated as PIPELINE INSPECTION GAUGE

Pneumatic or Hydro Test

The hydro test is to inspect or to check the strength of pipeline according to requirement by filling water & then giving the pressure by PCD (pressure Controlling Device)

What are the Hazards?

  • High-pressure burst by a sudden increase of pressure,
  • Loose connection of hose,
  • The gasket can break,
  • And the effect of the hazard can be from injury to death

What are the Safety Precautions?

  1. Inspection of all testing equipment &devices before each time to start work and pressure should gradually increase,
  2. The calibrated pressure gauge should install on line.
  3. The hose should secure with whip latches.
  4. Pressure controlling device place minimum TEN-10 feet away


  • Unauthorized work activity
  • Inadequate test equipment
  • Pipework under pressure
  • Unauthorized entry
  • Damage hose
  • Overpressure
  • Personnel injury
  • Property damage
  • High-pressure leaks
  • Damaged test pressure gauges,
  • Test pump,
  • Blinds,
  • Flanges,
  • High-pressure hoses, gaskets & connections.
  • Leading to sudden failure and discharge of parts of the system
  • Filling & Dewatering from pipelines

Hydro Test Formula: (0.15) x (D) x (a) ^ 0.4 x (p) ^ 0.6

D: Internal diameter
A: Length/diameter of a piece (m)
P: Test pressure (Bar)

Knowledge Point:

  1. Hydro test periods: steel tank should be every 5 years, fiber
  2. wrapped every 3 or 5 years (depending on DOT-E regulatory if
  3. unsure shall be every 3 years)

Why is Nitrogen Used for Pressure Testing?

The two main areas of Nitrogen gas are used within Heating, ventilation, and air conditioning (HVAC) are for brazing and pressure testing copper coil. Nitrogen [N2] is used during the brazing process to purge oxygen O₂ from the brazed surface. Nitrogen [N2] also prevents the formation of moisture during the leak testing process, thereby eliminating oxidation of the metal

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