Mazco Products and Services

Get to know the Safe-T-Stopper line stopping tool

Can the line stopper tool be used on service items other than in the natural gas industry?

Yes. The medium can also be liquids as long as the fitting type or configuration is suitable for tool attachment.

What are some of the uses for this tool?

Safe-T-Stopper can be used to eliminate worker exposure to hazardous releases of natural gas when working on main line service tees.
The tool can be fitted onto the service tee to either remove it or perform downstream work and return the tee to service. Service line alterations, dresser style compression fitting removals, etc. are possible without the release of natural gas. The tool is currently capable of interrupting fluid service to replace defective full port valves.
Safe-T-Stopper eliminates the need to shut down the main line or install stopper fittings on the main line to perform work on service tees and service line piping. There is a significant reduction in excavation size compared to the space necessary to install main line stopper equipment.

What is the intended purpose of this tool?

The tool was designed to address the difficulty in safely stopping homemade open gut or other manufactured service tees, including street tees, on natural gas service lines. The tool is capable of interrupting the supply of gas to service lines to perform service alterations or abandonments, without stopping the main gas line.
Eliminating worker exposure to hazardous releases of natural gas was a main driver in the development of the tool technology.
Releases of gas into the atmosphere was also a consideration in reducing Green House Gas (GHG) emissions.

Can a pipe plug be placed in main holes that were torched or punched?

Yes. Mazco manufactures certain overdrilling tools to drill concentric holes for installation of the plugs.

Will the tool work on street tees threaded into couplings welded on the main?

Yes. Mazco manufactures special half collars for couplings to allow street tee removal from the coupling and placement of a plug in a gas-free environment.

Is there a stub left on the main line after the service tee is removed?

Yes for certain applications. There is approximately 2" of stub that holds the drive-in and tapered weld plug on home made pipe tees. Owners may decide to use different tee closure devices such as threading the stub or using a compression fitting cap end.
For street tees on saddles that have been removed, operators will place their final closure saddle or threaded plug directly into the main.

What size main lines can the tool be used on?

Any size. Contact the supplier to discuss alternate service tee types or applications of service.

What is the maximum rated operating pressure of the tool?

The tool is currently rated for a maximum operating pressure of 550 kPa, (80 psi) for pipe type service tees.
Street tees or other applications may have a lower maximum operating pressure.
Contact the distributor for more information.

Will the tool work on saddle clamp fittings?

Yes, the tool will adapt to street tees threaded into saddle clamps.

Will this tool remove street tees threaded into cast iron mains?

Yes, a plug is then put back into the threaded opening.

What sizes of Safe-T-Stopper® are available?

The Safe-T-Stopper® comes in 2 sizes
The ¾" to 1 ¼" Safe-T-Stopper® attaches to:
  • ¾", 1" and 1 ¼" homemade open gut pipe type service tees
  • ¾", 1" and 1 ¼" Mueller no-blo service tees with brass completion plug intact
  • ¾", 1", 1 ¼", 1 ½" and 2" pipe threads
  • ¾" Mueller no-blo with brass completion plug missing
The 1 ½" to 2" Safe-T-Stopper® attaches to:
  • 1 ½" and 2" homemade open gut pipe type service tees
  • Attaches to ¾", 1", 1 ¼", 1 ½" and 2" pipe threads
  • 1" and 1 ¼" Mueller no-blo service tees with brass completion plug missing.
  • ¾", 1" and 1 ¼" Mueller no-blo service tees with brass completion plug intact
  • 1" to 2" street tees


Contact Mazco Products and Services Ltd. for more information

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