Instrument Installation

DOE-HDBK-1132-99

4.9

Instrument Installation . This section provides guidance for the installation of field

instrumentation, its associated tubing and location, and specific details about commonly

used pressure, level, flow, and temperature instruments.

4.9.1

General. Impulse tubing and valve material may differ from piping of the process

system they serve, but generally they equal or exceed the parameters of the

process system with respect to material, temperature, and pressure ratings.

Consider the use of expansion loop or flexible metal hoses on impulse

and sample lines where thermal or seismic movement is a concern.

Provide sensing lines with continuous slope to promote their being either

full or free of liquid as appropriate. The recommended slope is 1 inch per

foot. For instruments sensing steam up to 20 psia, the recommended

minimum slope is 2 inches per foot.

Prevent instrument tubing from coming in contact with structural steel and

concrete (painted or unpainted) surfaces of building members, except for

penetrations requiring closure. For tubing below 200 EF, grout may be

used for penetrations.

Tubing installed in exposed locations subject to accidental crushing or

damage should be protected by structural channels or tube track. This

type of protection should not render the tubing and fittings inaccessible.

Capillary tubing sealed to the instrument by the manufacturer should not

be cut during or after installation unless specifically required by the

installation drawing or manufacturer' instruction (e.g., capillary system

through a penetration).

4.9.2

Instrument Location . When locating instruments consider the following:

routing of sensing lines from the process tap to the instrument;

sensing line penetration through walls and floors;

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