All impulse piping in general be given a slope of not less than 1 in 12 except where
otherwise specified. The slope of impulse pipe work shall be down from the tapping
point for liquids and up from the tapping points for gas service unless special
provisions are made for venting and draining. For steam and Condensable impulse
lines should be raised to same height to compensate for differential and bring down
through condensing pots.
Sitting of vents and drains shall be ensured at the highest and lowest points of
piping run respectively.
Impulse pipe lines shall be kept as short as possible consistent with good practice
Handrails or process piping shall not be used as support to instrument impulse
lines unless otherwise specified.
Piping and tubing shall be adequately supported and fixed at distances not
exceeding limits as shown in figure.
Galvanized cable trays shall be used for continuously supporting four or more
copper tubes and copper tubes shall be secured to the tray at 0.5 m interval.
Use of multicore PVC tubes shall be preferred where multiple signals are
Trays supporting tubing shall be run with the breadth of the tray in vertical plane. If
in horizontal plane the tray shall be provided with additional support to prevent
All trays and supports shall be securely fixed to structural steel work or masonary
as per normal practice.
Impulse pipes shall be routed away from hot environment, places with fire hazards,
spilled liquids and where they are subject to mechanical abuse.