Case Study
Hydratight Mechanical Connectors
facilitate industry first hot-work free
platform shutdown
The Challenge
A Shell/ Esso operated sole pit clipper platform in the southern North Sea
required twenty six pipework tie ins. The work had to be completed within a
tight 10 day shutdown to minimise loss of production.
The Solution
Hydratight and AMEC Process and Energy Limited were engaged to
undertake an industry first hot-work-free platform shutdown using Hydratight
Morgrip™ Mechanical Connectors.
Hydratight’s Morgrip™ Connector is a DNV GL- and Lloyd’s Register
approved permanent alternative to conventional welded joints. The solution
eliminates hot-work for pipework tie-ins and is up to 10 times faster than
welding – reducing shutdown times significantly or avoiding the need for
shutdowns entirely.
Zero leakage is becoming increasingly important, not only for environmental
reasons, but also for hazard and explosion analysis. AMEC and Hydraight
invited Shell UK Exploration and Production Limited, and DNV, to a Factory
Acceptance Test (FAT) to demonstrate the leak free sealing performance of
the Morgrip™ Connectors used for the clipper shutdown. The test used a 1%
helium/nitrogen mix to a test pressure of the pipe. With the spectrometer set
at natural background levels no leakage was detected.
All Hydratight Morgrip™ Connectors undergo a Factory Acceptance Test
prior to shipment. This combined with the Connector’s external pressure test
facility meant there was no need for a time-consuming hydrotest of each
system after fitting the Morgrip™ Connector.
Above Final pressure testing of the fully
installed Morgrip™ Flange Adaptor.
Below Fully operational Morgrip™ Coupling.
Hydratight and AMEC’s preparatory work ensured the connections were
completed in a fraction of the time needed to weld. A total of 16 connectors
were used ranging from 2" to 16" all on SCH 120/160 900lb rated process
gas pipe work, and the remaining ten connections used standard flanges.
All hot-free work was performed successfully in just 10 days. All joints
passed nitrogen testing on the first attempt and there was sufficient time left
for additional nitrogen testing on the other systems.
“With the constrained shutdown resource
levels, making the connections by
traditional welding methods would
have taken an estimated 23 days.”
Jim Keeble
Project Manager for AMEC
Following the sole pit clipper shutdown, AMEC produced a set of guidelines
for installing Morgrip™ Connectors. The following page presents a table
comparing the actual time of connection for the Mechanical Connector
tie-ins, with the equivalent time projections for a welded connection.
continued on page 2
continued from page 1
Tie-in Description
TP-1 & TP-2 (12")
TP-3 & TP-4 (16")
TP-5 & TP-6 (3")
TP-10 & TP-11 (12")
TP-12 & TP-13 (16")
TP-14 & TP-15 (12")
TP-24 & TP-25 (2")
TP-26 & TP-27 (2")
Direct man hours
Non productive man hours
Planned man days
Planned shutdown duration
including 1 day degas &
2 days repressurise platform
Welding Flanges
Direct man hours (+)
244.21
314.08
54.98
244.21
314.08
244.21
49.56
49.56
621.1
608.75
360 days
Morgrip™'s
Direct man hours (*)
58.47
41.98
11.38
58.97
41.98
58.97
10.96
10.96
119.99
117.61
126 days
23 days
10 days
(+) Includes all activities, from initial pipe cut through to the flange pressure test ready
for system nitrogen test.
(*) Includes all activities, from initial pipe cut through to external pressure test ready
for system nitrogen test.
Jim Keeble, Project Manager for AMEC, said “With the constrained
shutdown resource levels, making the connections by traditional welding
methods would have taken an estimated 23 days.”
Mark Fisher, Senior Offshore Applications Engineer for Hydratight, said:
“The ability to undertake maintenance while platforms are in production
translates into £millions of increased revenue for operators. This industry first
hot-work free platform shutdown proves the flexibility, reliability and huge
revenue generating potential of weldless Morgrip™ Mechanical Connectors.”
For more information, visit hydratight.com.
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