Authority: IC 22-13-2-8

Affected: IC 22-15-6

Sec. 8. (a) Blow-off piping from a power boiler or a miniature boiler shall not discharge directly into a sewer.

(b) A blow-off tank shall be used where conditions do not provide an adequate and safe open discharge. A blow-off tank and associated piping shall meet the following requirements:

1. (1) The cross-sectional area of the outlet from the blow-off tank shall be twice the cross-sectional area of the inlet pipe and made to extend internally within eight (8) inches from the bottom of the tank.

2. (2) The vent pipe shall have a cross-sectional area at least four (4) times the cross-sectional area of the inlet pipe, or the blow-off tank shall meet one (1) of the following requirements:

   1. (A) It shall be constructed for a pressure equal to that allowed on the boiler to which it is attached.
   2. (B) It shall be equipped with a safety valve or valves of sufficient capacity to prevent the pressure from exceeding the safe working pressure of the tank.
3. (3) There shall be no valve or other possible obstructions, such as water pockets, between the tank and the discharge end of the vent pipe.
4. (4) All pipe connections between the tanks and the boiler shall be as direct as possible and shall conform to the ASME B&PVC.
5. (5) A manhole or an access opening shall be provided.

(Fire Prevention and Building Safety Commission; 675 IAC 30-5-8; filed Jan 5, 1996, 10:15 a.m.: 19 IR 1125; readopted filed Jul 9, 2001, 1:33 p.m.: 24 IR 3822; readopted filed Sep 21, 2007, 9:16 a.m.: 20071010-IR-680070389RFA; readopted filed Oct 19, 2007, 1:08 p.m.: 20071114-IR-680070389RFA; readopted filed Sep 5, 2013, 10:09 a.m.: 20131009-IR-680130182RFA; readopted filed Sep 4, 2019, 2:20 p.m.: 20191002-IR-675190336RFA; filed Apr 28, 2021, 11:03 a.m.: 20210526-IR-675200627FRA, eff Jul 1, 2021; readopted filed Nov 18, 2025, 10:36 a.m.: 20251210-IR-675240566RFA) NOTE: Transferred from the Boiler and Pressure Vessel Rules Board (680 IAC 2-5-8) to the Fire Prevention and Building Safety Commission (675 IAC 30-5-8) by P.L.249-2019, SECTION 15, effective July 1, 2019.