Page 139 - GRINNELL Mechanical Grooved Piping Products EMEA

Pressure and Design Data
Vertical Piping
Tech Data Sheets: G810, G820, G830
Risers comprised of rigid couplings can be considered instead of welded or flanged systems. Where thermal movement exists, expansion joints and/or flexible couplings with offsets may
be required.
When using flexible couplings, the movement that occurs in long lengths of piping needs to be considered. Each joint can move up to the maximum pipe end separation published. This movement can accumulate and result in the growth of the piping system,
for example at the top. Offsets may be necessary.
Should the riser contain branch connections, the movement which occurs at these locations with flexible couplings will also need to be considered.
One solution would be to anchor the vertical piping at appropriate locations to prevent movement which can cause stresses at
the branches or equipment. The use of rigid couplings can be
an advantage.
As always, good piping practise should prevail. It is the designer’s responsibility to select products suitable for the intended service and to ensure that pressure ratings and performance data is not exceeded. Never remove any piping component or correct or modify any piping deficiencies without first depressurising and draining the system. Material and gasket selection should be verified to be compatible for the specific application.
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