SPS 340.52(1)(c)1.b.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. SPS 340.52(1)(c)2.2. ‘Purging procedure.’ The piping system shall be purged in accordance with one or more of the following: SPS 340.52(1)(c)2.a.a. The piping shall be purged with fuel gas and shall discharge to the outdoors. SPS 340.52(1)(c)2.b.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. SPS 340.52(1)(c)2.c.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. SPS 340.52(1)(c)2.d.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. SPS 340.52(1)(c)2.e.e. The piping shall be purged by the gas supplier in accordance with written procedures. SPS 340.52(1)(c)3.3. ‘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. SPS 340.52(1)(d)(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. SPS 340.52 NoteNote: See Appendix for further information relating to purging.
SPS 340.52(2)(2) LP containers. This is a department informational note to be used under NFPA 58 section 5.2: SPS 340.52 NoteNote: 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. SPS 340.52 Note(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.”
SPS 340.52(3)(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. SPS 340.52 HistoryHistory: 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. SPS 340.53SPS 340.53 Fuel supply tanks for liquefied petroleum cargo tank trucks. No liquefied petroleum gas cargo tank that exists on or after September 1, 2011, may be connected in any way to a liquefied petroleum gas fuel supply tank for a motor vehicle. SPS 340.53 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.60(1)(1) Application. This subchapter applies to the storage, handling and use of liquefied natural gas. SPS 340.60(2)(2) Exemptions. This subchapter does not apply to any of the following: SPS 340.60(2)(a)(a) Liquefied natural gas systems owned and operated by utilities when the systems are part of the distribution facilities for the utility and are subject to the provisions of ch. PSC 135. SPS 340.60 NoteNote: Liquefied natural gas systems owned and operated for utility purposes by utilities are regulated by the Public Service Commission and are subject to chapter PSC 135, and the Natural Gas Pipeline Safety Act of 1968 (49 USC 1675, 49 CFR 192 - et seq.). SPS 340.60 NoteNote: The transportation of liquefied natural gas is subject to the regulations of the federal Department of Transportation under Title 49 CFR Parts 171-179. SPS 340.60 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.61SPS 340.61 Design, construction, installation, operation and maintenance of liquefied natural gas systems. Liquefied natural gas systems shall be designed, constructed, installed, operated and maintained as specified in NFPA 52 and 59A, except as otherwise provided in this chapter. SPS 340.61 NoteNote: Section SPS 340.42 contains requirements for vehicle-fuel dispensing systems. SPS 340.61 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.70(1)(1) Application. This subchapter applies to the storage, handling and use of compressed natural gas. SPS 340.70(2)(2) Exemptions. This subchapter does not apply to any of the following: SPS 340.70(2)(a)(a) Compressed natural gas systems owned and operated by utilities when the systems are part of the distribution facilities for the utility and are subject to the provisions of ch. PSC 135. SPS 340.70 NoteNote: Compressed natural gas systems owned and operated for utility purposes by utilities are regulated by the Public Service Commission and are subject to chapter PSC 135, and the Natural Gas Pipeline Safety Act of 1968 (49 USC 1675, 49 CFR 192 - et seq.). SPS 340.70 NoteNote: The transportation of compressed natural gas is subject to the regulations of the federal Department of Transportation under Title 49 CFR Parts 171-179. SPS 340.70 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.71SPS 340.71 Design, construction, installation, operation and maintenance of compressed natural gas systems. Compressed natural gas systems shall be designed, constructed, installed, operated and maintained as specified in NFPA 52, except as otherwise provided in this chapter. SPS 340.71 NoteNote: Section SPS 340.42 contains requirements for vehicle-fuel dispensing systems. SPS 340.71 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.80(1)(1) Application. This subchapter applies to the storage, handling and use of gaseous hydrogen. SPS 340.80(2)(2) Exemptions. This subchapter does not apply to any of the following: SPS 340.80(2)(a)(a) Gaseous hydrogen systems owned and operated by utilities when the systems are part of the distribution facilities for the utility and are subject to the provisions of ch. PSC 135. SPS 340.80 NoteNote: Gaseous hydrogen systems owned and operated for utility purposes by utilities are regulated by the Public Service Commission and are subject to chapter PSC 135, and the Natural Gas Pipeline Safety Act of 1968 (49 USC 1675, 49 CFR 192 - et seq.). SPS 340.80 NoteNote: The transportation of gaseous hydrogen is subject to the regulations of the federal Department of Transportation under Title 49 CFR Parts 171-179. SPS 340.80 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.81SPS 340.81 Design, construction, installation, operation and maintenance of gaseous hydrogen systems. Gaseous hydrogen systems shall be designed, constructed, installed, operated and maintained as specified in NFPA 52, except as otherwise provided in this chapter. SPS 340.81 NoteNote: Section SPS 340.42 contains requirements for vehicle-fuel dispensing systems. SPS 340.81 NoteNote: See chapter SPS 341 for registration and inspections of gaseous hydrogen pressure vessels that are not within the scope of this chapter.
SPS 340.81 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.90(1)(1) Application. This subchapter applies to the storage, handling and use of liquefied hydrogen. SPS 340.90(2)(2) Exemptions. This subchapter does not apply to any of the following: SPS 340.90(2)(a)(a) Liquefied hydrogen systems owned and operated by utilities when the systems are part of the distribution facilities for the utility and are subject to the provisions of ch. PSC 135. SPS 340.90 NoteNote: Liquefied hydrogen systems owned and operated for utility purposes by utilities are regulated by the Public Service Commission and are subject to chapter PSC 135, and the Natural Gas Pipeline Safety Act of 1968 (49 USC 1675, 49 CFR 192 – et seq.). SPS 340.90 NoteNote: The transportation of liquefied hydrogen is subject to the regulations of the federal Department of Transportation under Title 49 CFR Parts 171-179. SPS 340.90 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. SPS 340.91SPS 340.91 Design, construction, installation, operation and maintenance of liquefied hydrogen systems. Liquefied hydrogen systems shall be designed, constructed, installed, operated and maintained as specified in NFPA 52, except as otherwise provided in this chapter. SPS 340.91 NoteNote: Section SPS 340.42 contains requirements for vehicle-fuel dispensing systems. SPS 340.91 NoteNote: See chapter SPS 341 for registration and inspections of gaseous hydrogen pressure vessels that are not within the scope of this chapter.
SPS 340.91 HistoryHistory: CR 11-002: cr. Register August 2011 No. 668, eff. 9-1-11. Appendix
The material contained in this appendix is for clarification purposes only and is numbered to correspond to the number of the rule as the rule appears in the text of this chapter.
A-340.52 (1) (a) The process of purging gas piping of fuel gas or charging gas piping that is full of air with fuel gas must be performed in a manner that will minimize the potential for a flammable mixture to be developed within the piping. Also, a significant amount of flammable gas should not be released within a confined space. Natural gas and propane suppliers add a distinctive odor to their gas to aid in its detection. However, when a new system is brought into service and non-odorized gas is detected, the company supplying the gas should be informed of the situation to determine what action should be taken.
(b) 1. Section SPS 340.52 (1) (b) 1. describes the characteristics of gas piping systems that are required to be purged only to the outdoors. The criteria were selected to distinguish between piping systems located in industrial, large commercial, and large multifamily buildings from those located in light commercial and smaller residential buildings. The gas piping systems installed in industrial, large commercial, and large multifamily buildings are considered to be larger, more complex systems for the purposes of defining their purging requirements. Because of their larger pipe volumes or potential for higher flow rates, these systems require procedures to ensure that large volumes of fuel gases are not released indoors and that flammable mixtures do not occur within the piping itself. Installers of these complex systems deal with considerably more variables that may result in a higher potential for discharge of large gas volumes during purging operations. Specific occupancy categories such as industrial, manufacturing, commercial, and large multifamily were not included in the fuel gas code. Building codes define these occupancies for the purpose of construction and safety requirements. There is no general relation between the occupancy types, as defined by building codes, and the size of gas piping system to be installed in that occupancy. The gas piping size and operating pressure are based on the nature of the piping system and gas appliances to be installed and are not dependent upon a building’s occupancy type or classification. 3. It is recommended that the oxygen levels in the piping be monitored during the purging process to determine when sufficient inert gas has been introduced. The manufacturer’s instructions for monitoring instruments must be followed when performing purge operations.
5. Combustible gas indicators are available with different scales. For purging, it is necessary to use the percent gas in air scale and to follow the manufacturer’s operating instructions. The percent LEL (lower explosive limit) scale should not be used as it is not relevant to purging.
(c) 1. The criteria were selected to describe typical gas piping systems located in light commercial and the smaller residential family buildings. Gas piping systems installed in these buildings are considered to be smaller and less complex systems for the purposes of defining their purging requirements. Installers have familiarity with purging these systems and the potential for discharge of large gas volumes during purging operations is low. Also see paragraph (b) 1. above.
2. Where small piping systems contain air and are purged to either the indoors or outdoors with fuel gas, a rapid and uninterrupted flow of fuel gas must be introduced into one end of the piping system and vented out of the other end so as to prevent the development of a combustible fuel and air mixture. Purging these systems can be done either using a source of ignition to ignite the fuel gas or by using a listed combustible gas indicator that can detect the presence of fuel gas.
