Hydrostatic Test & Isolation Plugs

Safe, effective solutions for rapid pipe testing and repairs

EST Group offers a complete line of Hydrostatic Pressure Test and Pipeline Isolation Plugs for hydropressure testing pipework, pipelines and pressure vessels.

  • Test Open End Pipe, Pipelines, Tubes and Pressure Vessels
  • Perform Flange-To-Pipe Weld Testing
  • Isolate and Test Pipe Connections

Hydro Test plugs for pipe provide safe and effective testing at working pressures up to 15,000 psi (1034 Bar). Pipe OD and ID sealing versions available.

Pipe isolation plugs are designed for quickly isolating and hydrostatically testing weld joints of any welded flange-to-pipe connection as well as isolating pipe ends during cutting, grinding and welding operations.

Also available are hydrostatic test pumps, ideal for use with our entire range of pressure test plugs.

griptight MECHANICAL PIPE plugs: pipe & hydro testing



The GripTight Isolation Plug is a one-tool solution that provides positive isolation and monitors potentially hazardous or explosive vapors upstream of a welding job, effectively hydro-testing the new weld connection. The plug features the GripTight gripper technology, a proven system with a 20-year track record of successful use in EST Group’s GripTight® Test Plugs.

The gripper system is designed for reliable sealing and adheres to the principle, “the greater the pressure, the greater the grip.” Therefore, if a faulty valve or another event should cause a rapid increase in the upstream pressure, the grippers use that pressure to increase their grip on the pipe’s inner diameter wall.

The grippers hold the GripTight Isolation Plug in place and withstand the full rated line pressure up to 1500 PsiG, thus preventing a failure that could damage the line or lead to serious injury for the onsite work crew.


Once the welding is complete, and the weld area has cooled to below 180°F (82°C), the seals are released, and the plug can be moved to reposition the isolation cavity over the weld. The plug is then reset and pressurized to test the integrity of the weld, up to a test pressure of 2250 PsiG. Pressure tests can be completed in as little as 10 minutes from insertion to removal.


our Griptight® pressure testing plugs

We offer a complete line of Hydrostatic Pressure Test and Pipeline Isolation Plugs for pressure testing pipework, pipelines, and pressure vessels in a high-pressure environment.



At Curtiss Wright, we have a wide selection of Griptight mechanical pipe testing plugs suitable for various applications. 


  • Reduces test times up to 80%
  • Eliminates welding end caps - no welding, grinding, or cutting required
  • Uses test pressure to grip more securely
  • Reusable, compatible with hydrostatic testing


  • Safe and reliable testing at higher pressures
  • The patented dual-serrated gripper design provides more gripping points on the pipe surface.
  • Hardened shaft, grippers, and cone increases durability, extends service life and reduces wear.
  • Ideal for hardened pipe applications up to HRC 32
  • Reusable, compatible with hydrostatic or pneumatic testing


  • Orientation free installation
  • Save significant time over welding end caps
  • Patented dual-serrated GripTightMAX grippers
  • Patented self-aligning gripper/seal design
  • Fits most long radius elbows
  • Reusable, compatible with hydrostatic or pneumatic testing


  • Monitor potentially explosive vapors during hot work
  • Minimize risk of accidental blowout/expulsion due to improper use or unexpected upstream pressure
  • Uses less than a gallon of water, reducing waste water, treatment expenses, and facilitates testing in remote areas of facilities
  • ASME PCC-2 Type IV testing device


Curtiss-Wright EST Group is dedicated to providing a complete range of lifecycle products and services to maintain and repair open-end pipes, piping systems, tubing, and pressure vessels for the following industries and applications worldwide.


  • Petrochemical & Refining
  • Oil & Gas Production
  • Power Generation
  • Design & Build Projects
  • Shipbuilding Industry
  • Industrial Contractors
  • Module Fabricators


What is a mechanical pipe plug?

Our Griptight plugs are more commonly known as mechanical pipe test plugs. Used in applications where safety is vital, the mechanical pipe plugs are actuated by tightening a series of rim nuts around the periphery of the pipe plug, sealing it for protection.