Page 91 - Facility Piping Systems Handbook for Industrial, Commercial, and Healthcare Facilities

PIPING

PIPING 2.41

Compression Sleeve Coupling
The compression sleeve coupling is a rigid, pressure-type joint, often used to connect plain
end fuel gas, air, oil, and water piping. This is a proprietary joint also known as Dresser
couplings, after the manufacturer of the joint.
This coupling uses a metallic middle ring with a gasket placed at each end. The gaskets
are compressed by means of a separate metallic gland placed over the gaskets and bolted
to each other across the joint.
This is a proprietary joint that has no standards governing fabrication. Refer to Fig. 2.15(b)
for an illustration of a compression sleeve coupling.

Plastic Insert Joint
The plastic insert joint is a rigid, pressure-type joint used to connect plain end, flexible
plastic tubing such as PEX for potable water service.
The joint is fabricated by placing an insert into both ends of the pipe to be connected,
bringing the ends together and securing the insert to each pipe end by means of a clamping
device or crimp assembly. For added strength, two clamping devices on each end are often
used. Refer to Fig. 2.15(c) for an illustration of a plastic insert joint.

Mechanically Formed Fittings

The mechanically formed joint is a rigid, pressure-type joint commonly used to provide a
branch connection in copper water piping. This joint shall only be brazed. This is a propri-
etary joint also known as T-Drill, after the manufacturer of the joint.
These joints are formed using a proprietary tool that first drills a pilot hole in the main
pipe and upon withdrawal extrudes a collar. The branch pipe to be inserted shall be dimpled
to form a depth stop, preventing the branch from being inserted too far into the main pipe
collar and restricting flow.
This is a proprietary joint that has no standards governing fabrication. Refer to
Fig. 2.15(d) for an illustration of a mechanically formed joint.

Memory Metal Fittings

This is a metallic, pressure type joint with fittings composed of an alloy of nickel and tita-
nium used to connect the ends of copper pipe containing compressed gas.
The joint is fabricated by using fittings kept in liquid nitrogen containers. The metal
expands when cold and shrinks when it reaches room temperature. The two ends of the pipe
are butted together with the fitting over the ends. When it becomes warm, the metal shrinks
over the ends and the joint is pressure light.
This is a proprietary joint that has no standards governing fabrication.

ADAPTERS

Adapters are required when joining pipes with different dimensions or different joint types.
Most plumbing codes require the use of approved adapters when joining two different pipe
materials or piping with dissimilar joint ends.

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