Columbia CDVB-100, Installation, Operation & Maintenance Manual, Page: 10 / 44

10
WARNING
To avoid burns, scalding, or water damage due to discharge of steam and/or hot water during operation, a
discharge line shall be installed to relief valve outlet connection.
Discharge line shall:
• connect to relief valve outlet and piped down to safe point of disposal. Check local codes for
maximum distance from floor or allowable safe point of discharge.
• be of pipe size equal to or greater than that of the relief valve outlet over the entire length of
discharge line;
• have no intervening shutoff valve between safety relief 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 the valve and the discharge line;
• be independently supported and securely anchored to avoid applied stress on the relief valve;
• be as short and straight as possible;
• terminate with plain end (not threaded);
• be constructed of material suitable for exposure to temperatures of 375° F; or greater.
Refer to local codes and appropriate ASME Boiler and Pressure Vessel Code for additional installation
requirements.
!
WARNING
Burn and scald hazard. Safety relief valve
could discharge steam or hot water during
operation. Install discharge piping per these
instructions.
11.
Install discharge piping from safety relief valve.
• Use ¾" or larger pipe.
• Use pipe suitable for temperatures of 375°F (191°C)
or greater.
• 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.
• Run pipe as short and straight as possible to location
protecting user from scalding and properly drain
piping.
• 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).
• Terminate pipe with plain end (not threaded).
CONNECTING SUPPLY & RETURN PIPING