Instrument Tubing

In-line instruments

All in-line instruments shall be installed in accordance with supplier recommendations.

Prior to final installation of control valve and other in-line instruments, process lines shall be
properly flushed.

Off-line instruments

Each instrument shall be available for maintenance and disconnection without interfering with the

The installation shall be arranged so that it can be heat traced and thermal insulation applied.

All indicating instruments which includes transmitters with indicators to be located between 1-1,8
m above deck level.

Direct mounted instruments shall be used whenever applicable.

Impulse tubing shall be as short as possible and be installed so that gas/liquid pockets are avoided.
Instruments shall be installed below tapping point for liquid service and above tapping point for gas

For some installations use of direct flange mounted capillary tubing is specified. The capillary will
be fixed to the instrument and flange by the manufacturer.

Impulse tubing shall have minimum 1:12 slope

Tubing installation

Instrument tubing shall be supported to field trays or cable ladders for tubing sizes less than 16 mm
outside diameter. Cable tray, ladder or equal to be used for larger sizes when mechanical protection
is required. Trays are not required for internal tubing on components if tubing is sufficiently

Tubing to be fastened to self drained tubing clamps with span max every 60 x tubing diameter.

Tubing sizes above 25 mm outside diameter shall as a minimum have support every 1.5 m.

Tubing clamps shall be made of non-corrosive material, stainless steel AISI 316 and/or flame
retardant plastic.

Galvanic corrosion between tubing and tubing support system shall be avoided. The tubing clamp
shall, when installed, not allow for water/sea water to be accumulated between tubing and
tubingclamp on wall, this is to avoid crevice corrosion.

Parallel runs of tubing on the same support shall be arranged such that it is possible to have access
to every connection point.

Installation into or through panels shall be by use of bulkhead unions or multi cable transits.

Instrument tubing and cables may be installed on the same field tray for shorter distances
(appr. 5 m). Instrument tubing and cables may be routed through the same cable/tubing penetration
provided the transit is approved for such use.

All tubing and/or tube fittings which are not connected shall be sealed by use of end-plug / cap of
some material as the tubing, fittings.

Vent, drain and manifold valves shall be available outside insulation for test connections. Tubing
shall be installed to reach outside insulation for test connections.

Capillaries of filled systems shall be continuously supported Spare capillaries shall be coiled inside
a cable tray or have similar mechanical protection.

All tubing shall be deburred and blown through with clean, dry air before final installation.

All compression tube fittings shall be of the same make.

The installation shall be done by skilled personnel being familiar with the requirements from the
compression fitting supplier.

All tubing in hydraulic systems shall be hot oil flushed and cleaned Sealing compounds for process services, instrument air services and hydraulic oil services shall be used in accordance with supplier recommendations.

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