Section 340.52. Amendments to NFPA standards.

 

(1)   Purging requirements. Substitute the following wording for the requirements in NFPA 54 sections 8.3.1 to 8.3.4:

(a) General. The purging of all piping, appliances and equipment that exist on or after September 1, 2011, shall be in accordance with this subsection.

(b) Piping systems required to be purged outdoors.

1. `Application.' The purging of piping systems shall be in accordance with subds. 2. to 5. where the piping system meets either of the following:

a. The design operating gas pressure is greater than 2 psi.

b. The piping being purged contains one or more sections of pipe or tubing greater than 2 inches in diameter and having the lengths in Table 340.52.

2. `Removal from service.' Where existing gas piping is opened, the section that is opened shall be isolated from the gas supply and the line pressure vented in accordance with subd. 4. Where gas piping meeting the criteria of Table 340.52 is removed from service, the residual fuel gas in the piping shall be displaced with an inert gas.

Table 340.52

Size and Length of Piping - See PDF for table

3. `Placing in operation.' Where gas piping containing air and meeting the criteria of Table 340.52 is placed in operation, the air in the piping shall first be displaced with an inert gas. The inert gas shall then be displaced with fuel gas in accordance with subd. 4.

4. `Outdoor discharge of purged gases.' The open end of a piping system being pressure vented or purged shall discharge directly to an outdoor location. Purging operations shall comply with all of the following requirements:

a. The point of discharge shall be controlled with a shutoff valve.

b. The point of discharge shall be located at least 10 feet from sources of ignition, at least 10 feet from building openings and at least 25 feet from mechanical air-intake openings.

c. During discharge, the open point of discharge shall be continuously attended and monitored with a combustible gas indicator that complies with subd. 5.

d. Purging operations introducing fuel gas shall be stopped when 90% fuel gas by volume is detected within the pipe.

e. Persons not involved in the purging operations shall be evacuated from all areas within 10 feet of the point of discharge.

5. `Combustible gas indicator.' The combustible gas indicator used during purging operations shall be listed and shall be calibrated in accordance with the manufacturer's instructions and recommended schedule. The combustible gas indicator used for pipe discharge monitoring shall numerically display a volume scale from 0% to 100% with a resolution of not greater than 1% increments.

(c) Piping systems allowed to be purged indoors or outdoors.

1. `Application.' The purging of piping systems shall be in accordance with subd. 2 where the piping system meets both of the following:

a. The design operating pressure is 2 psi or less.

b. The piping system being purged is constructed entirely from pipe or tubing of 2-inch nominal size or smaller, or larger pipe or tubing with lengths shorter than specified in Table 340.52.

2. `Purging procedure.' The piping system shall be purged in accordance with one or more of the following:

a. The piping shall be purged with fuel gas and shall discharge to the outdoors.

b. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through an appliance burner not located in a combustion chamber. The burner shall be provided with a continuous source of ignition.

c. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through a burner that has a continuous source of ignition and that is designed for such purpose.

d. The piping shall be purged with fuel gas that is discharged to the indoors or outdoors, and the point of discharge shall be monitored with a listed combustible gas detector in accordance with subd. 3. Purging shall be stopped when fuel gas is detected.

e. The piping shall be purged by the gas supplier in accordance with written procedures.

3. `Combustible Gas Detector.' The combustible gas detector used during purging operations shall be listed and shall be calibrated or tested in accordance with the manufacturer's instructions and recommended schedule. The combustible gas detector used for pipe discharge monitoring shall indicate the presence of fuel gas.

(d) Purging appliances and equipment. After the piping system has been placed in operation, appliances and equipment shall be purged before being placed into operation.

(2)   LP containers. This is a department informational note to be used under NFPA 58 section 5.2:

(3)   Relief valves. This is a department rule in addition to the requirements in NFPA 58 section 5.7.2.5: Any previously used relief valves that are reinstalled under this section shall be certified prior to that installation by their manufacturer or its authorized representative as conforming to the applicable requirements of ANSI/UL132 or other equivalent pressure-relief-valve standard.

CR 11-002 : cr. Register August 2011 No. 668 , eff. 9-1-11; correction in (1) (b) 1. b., 2., 3., (c) 1. b. made under s. 13.92 (4) (b) 7. , Stats., Register December 2011 No. 672 .

Note

See Appendix for further information relating to purging. Microsoft Windows NT 6.1.7601 Service Pack 1 Section 101.16 (3) of the Statutes contains requirements for LP gas containers, and reads as follows: " FILLING, EVACUATING, AND USE OF CONTAINERS. (a) Except as provided in par. (b), no person, other than the owner of a liquefied petroleum gas container or a person authorized by the owner, may fill, refill, evacuate, or use in any other manner the container for any purpose. Microsoft Windows NT 6.1.7601 Service Pack 1 (b) A retail supplier may evacuate a liquefied petroleum gas container not under its ownership in order to transfer the remaining liquefied petroleum gas that is in that container into a container that is under its ownership." Microsoft Windows NT 6.1.7601 Service Pack 1