Taking note of NFPA 58 changes

June 1, 2008 By    

Many changes were made in the 2008 edition of NFPA 58, Liquefied Petroleum Gas Code. Major changes of interest to propane marketers are listed here, with some reasons why they were made. A more complete list of changes has been included in the 2008 edition of the Liquefied Petroleum Gas Handbook, available from NFPA.

Theodore C. Lemoff
Theodore C. Lemoff

Cabinet heaters are not included. There has been extensive discussion of this subject, and therefore not included in this article. Composite cylinders were not added to NFPA 58, but they can be used anywhere metal cylinders can be used, as they are DOT cylinders, and NFPA 58 allows all DOT cylinders.

1. Temporary installations. The maximum duration of a temporary installation was changed to 12 months. In the 2004 edition, the definition of temporary installations stated six months, but elsewhere in the code they were allowed to be 12 months. Enforcers believed that temporary installations should be limited, and that any installations beyond six months should follow the permitting and approval requirements of the code. Marketers agreed that there should be a limit to temporary installations, but believed that many truly temporary installations, such as construction heating, required more than six months.

2. Notification of new railcar transfers. This new paragraph (4.3.2) requires that the authority having jurisdiction be notified of the first transfer from a railcar in a new installation. Permitting has been required, but up until now the authority having jurisdiction might not have been aware that product was being transferred until after some time. The requirement was requested by a local authority that inspects new installations but was not notified of its startup.

3. 100-pound cylinders without fixed maximum-level gauges. Previously, all 100-pound cylinders were required to have a fixed maximum liquid level gauge (spit gauge). Many cylinders in industrial gas service are filled by weight only. These do not have fixed maximum level gauges, and the industrial gas companies that use them have a large inventory of such cylinders. The committee did not see why a fixed maximum liquid level gauge should be required for cylinders used by companies that fill by weight. Marketers should be aware that they may receive cylinders that do not have this gauge. These must be filled by weight.

4. Container appurtenance table. The container appurtenance table (Table 5.7.4.1) was completely revised and simplified to have fewer columns and rows. The table is used mostly by suppliers who provide cylinders complete with appurtenances (valves, level gauges, etc.).

Figure 1
Figure 1

5. Threaded internal valves. A threaded internal valve in the open position (shown in Figure 1) is equipped with a manual operator. When this valve is installed in a propane tank, it is threaded into an existing tank fitting. Newer tanks have a half-coupling welded to provide the thread; older tanks use a full coupling. The flow though the internal valve will depend on the type of coupling. Figure 2 shows the same internal valve threaded into a halfcoupling. Figure 3 shows the same valve threaded into a full coupling. Note the opening through which the liquid propane flows is within the coupling in Figure 3, restricting the flow of liquid. The flow is not restricted with a half-coupling. Manufacturers of internal valves provide flow information for their valves with different values for both situations.

Figure 2
Figure 2

6. Higher pressure in buildings. A new requirement (6.9.1.2) specifically allows propane vapor to be piped in industrial occupancies between 20 and 50 psi. The previous limit was 20 psi, and the relatively few high-pressure installations had to be permitted using the Equivalency Section (1.5). This required extensive discussion with the authority having jurisdiction, which sometimes arbitrarily rejected the permit. The committee saw no reason to prohibit higher pressures in industrial occupancies only, where precautions are taken to prevent the vapor from liquefying.

Figure 3
Figure 3

7. Flexible connectors. Several changes were made:

  • Two sub-definitions were added: flexible hose connector and flexible metallic connector.
  • Flexible metallic connectors are now limited to 5 feet, up from 3 feet.
  • Flexible connectors for pumps must be flexible metallic connectors.
  • Flexible connectors for compressors can be flexible metallic connectors or flexible hose connectors.

After completion of these changes, we became aware that the changes may have unintentionally added new restrictions, which may prohibit some new products, and I expect further revisions to this area in the next edition.

8. Remote shutoff actuation. A new section (6.10) allows propane vapor to be used as a pressure source to operate internal valves and emergency shutoff valves. This has been done in warmer areas in place of air compressors or nitrogen cylinders. While not prohibited, many marketers and enforcers were reluctant to use it if not specifically allowed in NFPA 58. The committee saw no reason to reject the proposal, especially where the requirements limited discharge to the atmosphere in the event of tubing breakage.

9. Debris in piping – retroactive. Piping systems must prevent debris that could impede valves from functioning properly. In plain English, you need a strainer in any piping system that is open, such as piping to or downstream from a transfer hose. The type of strainer is not specified, so any strainer or other device can be used. The committee felt this was important enough to make it retroactive to all installations by July 1, 2011, the date for all bulk and industrial plant containers to have internal valves.

10. Security – guard service. If a plant has a guard service – full time, part time or just drive-by checks – the guards must be trained. Guards would only have to be trained in aspects of the plant that they are active. If they walk through a plant, they should be trained to recognize hazards and in the operation of all safety devices they might operate. If they drive by a plant, they should be trained in the operation of any emergency shutoff devices. All guards should be instructed who to notify if something abnormal is observed.

11. Patio heaters. New section (6.19.9) added to cover patio heaters with propane tanks. Only listed patio heaters can be used, and they must be at least 5 feet from exit doors in a restaurant or other building open to the public. Some officials have applied rules from fire codes to restrict patio heater installations that posed no fire threats.

12. Cargo tank to cargo tank transfer. This new requirement recognizes the use of cargo transports as temporary storage and requires odorization verification. Pull-away protection must be provided, and the DOT requirements for passive shutdown of transfer must be installed. While there was some support to prohibit this type of transfer, essentially allowing a company to operate without a bulk plant, it was recognized that there are times when such transfer is legitimate and safe. Basically, all the safety requirements for bulk plants must be provided. Testing and repair operations are excluded.

13. Small LP gas systems. A new, separate section (14.4) in the operations and maintenance chapter provides requirements for operators of systems serving 10 to 99 users. These requirements are not new; they are an updated condensation of the existing DOT requirements that have been in effect for over 25 years. The section was added because the committee believed many system operators were unaware of the DOT requirements.

Theodore C. Lemoff is the principal gases engineer for the National Fire Protection Association.

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