Installation guidelines for sensing line installation

Guideline for sensor line:


  • Instrument sensing lines should be installed in accordance with the guidance presented in LANL Engineering Standards Manual ISD 341.2.

  • Sensing installation manner shouldn’t interfere with the future preventive maintenance procedure.Minimum headroom clearance should be 7 feet for recognized and recognized passages.

  • Instrument sensing lines should be routed separately from process lines and equipment where vibration, abnormal heat, or stress could affect the lines.

  • Instrument sensing lines routed through penetrations, shield walls or other obstacles where visual contact is impaired or lost should be marked with a continuous tag safely connected to each side of the barrier showing the appropriate device identification.

  • The distance between the sensing lines should always be sufficiently large to allow each tube to grow separately at all times without hitting neighbouring pipes or other machinery.

  • Before the device is put into service, sensing lines should be kept clear of any foreign material with clean, oil-free, dry air or nitrogen.

  • The sensing line should sufficiently slope to make a free path to the liquids, Line should be free of fluids.

  • Heat tracing should be used to detect liquid-containing lines that may freeze or become viscous, or wet gas from which humidity may condense.

  • Bends, rather than tube or pipe fittings, should be used to change the direction of sensing lines. The cold bending method is advised for all bends.

  • For threaded connections of stainless steel to stainless steel, lubrication should be applied to prevent seizing and galling. Low or no chloride content lubricants should be used with stainless steel.

  • Unless specifically needed by the installation drawing or manufacturer’s instructions, capillary tubes attached to the tool by the manufacturer should not be opened or trimmed during or after installation. Slope requirements do not apply to capillary tubing.

  • Primary sensing lines at local panels and racks should be neatly arranged with easy access to test, drain, and vent connections, instruments valves, and manifold.