Operation and Installation Manual

13
10. Install discharge piping from safety relief valve.
• Use ¾” or larger pipe. See Figure #11.
• Individual boiler discharge piping shall be
independent of other discharge piping.
• Size and arrange discharge piping to avoid
reducing safety relief valve relieving capacity
below minimum relief valve capacity stated on
rating plate.
• Install union, if used, close to safety relief valve
outlet.
• Install elbow(s), if used, close to safety relief valve
outlet and downstream of union (if used).
SYSTEM PIPING
Check local
codes for
maximum
distance
from oor
or allowable
safe point of
discharge.
SAFETY RELIEF VALVE
DISCHARGE
PIPING
Figure #11 - Discharge Piping From Safety
Relief Valve
WARNING
Burn or Scald Hazard. Discharge line shall be installed to relief valve outlet connection to avoid burns,
scalding, or water damage due to discharge of steam and/or hot water during operation.
Discharge line shall:
• Connect to safety valve outlet. Piped down to safe point of disposal. Check local codes for maximum
distance from oor or allowable safe point of discharge.
• Pipe size be of equal to or greater than of safety valve outlet over entire length of discharge line.
• Have no intervening shutoff valve between safety valve and discharge to atmosphere. Do not plug or
place any obstruction in discharge line.
• Terminate freely to atmosphere where any discharge will be clearly visible and at no risk of freezing.
• Allow complete drainage of valve and discharge line.
• Install safety valve with spindle in vertical position.
• Do not install shutoff valve between boiler and safety valve.
• Support safety valve discharge piping.
• Be short and straight as possible.
• Terminate with plain end, not threaded.
• Constructed of material suitable for exposure to temperatures of 375° F (191°C); or greater.
Refer to local codes and appropriate ASME Boiler and Pressure Vessel Code for additional installation
requirements.
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