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G-LOK ®
– The Advantages
The G-LOK ® Connector is designed to offer the strength and sealing integrity of
a welded joint and the versatility of a mechanical joint. It serves the same
purpose as a bolted flange assembly, with the advantages of being more easily
installed, lighter and smaller.
A self-energized, pressure activated connection, the G-LOK ® clamp-type
connector consists of four basic elements:
• (1) Hub
• (2) Clamps
• (3) Seal
• (4) Bolting
G-LOK ® std free position
The hubs are usually welded to pipe; the seal is installed and the bolting is
tightened on the clamps to form a pipe connector that provides superior
strength and leak integrity. The G-LOK ® is commonly used in service with
temperatures of up to 650°C. The G-LOK ® also
excels in high pressure applications, where
working pressure of 30,000 psi is not
uncommon.
The G-LOK ® clamp has been designed for the
optimum strength of a bolted connection.
Since the bolts are perpendicular to the axis of
the pipe, they do not receive direct bending
and pressure loads. This system of clamping
provides greater strength than ANSI or API
G-LOK ® std made-up position flanges at a fraction of the seal size and
weight as a result of this design. Less bolting
torque is required for proper seating of the seal.
The design of the connector provides considerable stored energy in the system G-LOK ® recessed free position
when compared with ANSI or API flanges. This stored energy works to provide
leak resistance during thermal cycling and
maintains proper bolt loading.
When properly installed, the G-LOK ® will
usually provide greater bending and torsional
strength than the connecting pipe. The full
face contact of the connector resists bending
and ensures rigidity not provided by other
clamp-type connectors. The pressure and
temperature limitations are determined only
by the materials of construction.
G-LOK ® recessed made-up position
4
G-LOK ® shrouded free position
G-LOK ® shrouded made-up position
HOW THE G-LOK ® CONNECTORS SEALS
The seal ring in the G-LOK ® resembles a ”T” in cross section. The base of the ”T”
is the rib that is held by abutting hub faces as the connection is made up. The
top of the ”T” forms the lips that seal against the inner surfaces of the hubs.
In the assembly of the connection, the clamps fit over the two hubs, and as they
draw the hubs together the seal ring rib ensures proper seal alignment.
As the hubs are drawn together by the clamp assembly, the seal ring lips deflect
against the inner sealing surfaces of the hubs. This deflection elastically loads
the lips of the seal ring against the inner sealing surface of the hub, forming the
self-energized seal. Internal pressure reinforces this seal, so the sealing action of
the G-LOK ® is both self-energized and pressure energized.
G-LOK ® clamp connectors are interchangeable with other connectors designed
and manufactured according to the same standard.