OPD History - web page - National Propane Gas Association

The OPD: A Short History

Prepared Under the Direction of Charles R. Revere,
President of the National Propane Gas Association
July 2000

Introduction

Over the years, the liquefied petroleum gas (LPG) industry has been very active in promoting and implementing goals that address safety practices in the handling, storage, transportation and application of its primary commodity, propane. Historically, the National Propane Gas Association (NPGA), engaging in the discipline of safety as one of its prominent cornerstones, has been the leading organization in accomplishing these efforts.

Accordingly, the overfilling prevention device (OPD) has been conceived and developed to advance safety in a manner that complements LPG cylinder filling education and training programs. It must be recognized that during the 1990's, circumstances regarding this new LPG hardware forged ahead and its use was impending, irreversibly. Forces were surfacing that threatened to create a firestorm of immediate and disorganized implementation of the OPD. A drive was also engaged to create more unnecessary, ineffective and unenforceable regulation onto the marketers of LPG. Before this nightmare peaked, NPGA begun a process to deal with the issue and was ready to fill a void of guidance and reason. The following is intended to provide a better understanding among consumers and members of the LPG industry about the influences that have been a part of bringing this safety device to its current status.

Some Background Is Helpful...

The documentary should begin by recalling the interest in propane motor fuel that gained a new impetus in the late seventies and early eighties. From the restored status of propane as a clean-burning, environmentally sound alternative engine fuel, some new safety conditions were adopted for carburetion applications. One of these advances became mandatory in the National Fire Protection Association's (NFPA) Propane Code (Code), which called for an "automatic means to prevent filling in excess of the maximum permitted filling density". This applied to all engine fuel containers manufactured after January 1, 1984. Initially, some problems in the field were experienced with these devices. But in time, greatly reducing the potential for overfills in engine fuel containers, they have become a positive contribution to safety.

Fostered by the engine fuel experience throughout the 1980's, OPD's for small propane cylinders continued to be a subject deliberated by a task force of the NPGA's Technology and Standards Committee (T&S). It proved to be a formidable challenge for the task force and T&S to arrive at a consensus, as the science for the OPD had to employ a different set of conditions from engine fuel containers to portable cylinders.

Paralleling the T&S work, through statistical research and historical incident investigation, the U.S. Consumer Product Safety Commission (CPSC) published the results of a study. Conclusions drawn from the work included a recommendation to determine how best to reduce the number of incidents attributed to propane in the ever-growing and popular gas grill market. The potential for overfilled cylinders, an ongoing concern for NPGA and the industry, was now a focus of the CPSC. A section of the study dealt with high temperature cut-off devices, quick disconnects with automatic shutoff features, and stop-fill devices, all for small LPG cylinders. 2

And Then There Were Diversions...

Coincidentally, on the litigation scene in 1994, a class action suit in the Superior Court for the State of California for the County of Marin issued a settlement order in Case No. 157907 to several major manufacturers of propane gas barbecue grills and cylinders. As ordered by the court, the defendants were directed to comply with conditions that included the use of stop-fill devices, when they became commercially available, on propane gas grill cylinders.

By the year 1996, OPD's in their early configuration were marketed in the U.S. Hence, literally thousands of 20 lb propane gas cylinders were then fitted with these devices. Many of these valves had restricted flow capacities that precluded their use in some traditional applications and increased the time to purge a cylinder. Understandably, OPD's immediately received severe and deserved criticism. However, competition in the marketplace with new generation OPD's is progressively eliminating the earlier problems. Even so, users should be aware of the early valve's existence in the field, estimated to number in excess of 30,000. Although employing the OPD feature, they do not have the readily identifiable trilobular handwheel nor are they even subtly tamperproof. Eventually, these older units will become the victims of attrition.

On another front, in January and March of 1996, U.S. Representative Richard Burr (NC) submitted to the U.S. Department of Transportation a petition for rulemaking from the Barbecue Industry Association (BIA). The petition was forwarded to the Research and Special Programs Administration (RSPA), which published an Advanced Notice of Proposed Rulemaking (HM-220C) on Friday, August 23, 1996 in the federal Register, pp 43515-43517. BIA requested that the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) be amended to require: registration and training of persons who fill propane cylinders having a water capacity less than 200 lbs., which come under the jurisdiction of the DOT; certification of filling equipment; and proof of financial responsibility. The request stated that "RSPA may issue this registration based on an application and an inspection report of the facility used by the applicant and of the applicant's qualifications performed by an independent inspection agency approved pursuant to 173.300a, and any other information available to RSPA."

NPGA reacted quickly by appointing a task force to deal with the BIA petition, planning for a meeting with Congressman Burr, arranging a dialogue with BIA representatives, and establishing an industry position for filing with RSPA before the deadline of November 21, 1996. These plans were fulfilled. Based on substantive comments, NPGA strongly opposed the tenants of the petition and requested that it be denied.

The NPGA publication, Window On Washington (WOW), reported on 12/1/99, that the "Department of Transportation has announced that it will publish this month a notice ending its consideration of a petition submitted in 1996 by the BIA urging the registration and additional training of persons who fill propane cylinders." The notice of denial is expected to be published in 2000.

Even though out of calendar sequence, it should be noted here that during the course of the OPD activity, in 1997 the Recreational Vehicle Industry Association (RVIA) adopted a resolution requiring its members to use only cylinders equipped with OPD's. This association also submitted a proposed Tentative Interim Amendment to NFPA for the recreational vehicle standard NFPA 501C, that would mandate OPD's on all RV containers. Subsequently, the proposed TIA was rejected by NFPA.

So, in addition to the CPSC, the court system, Barbecue Industry Association (BIA), Recreational Vehicle Industry Association (RVIA), cylinder manufacturers and of course NPGA, the small cylinder safety issue had become a matter of examination by others. Included, were the Underwriters Laboratories, National Association of State Fire Marshals and the federal agency of the U.S. Department of Transportation.

A Time For "Getting On Board"...

Meanwhile, T&S continued its deliberations to reach a satisfactory conclusion on the many aspects of the OPD. Then, at New Orleans in May of 1996, NPGA's Board of Directors (Board) approved a plan recommended by the T&S Committee to file an OPD proposal with the NFPA before the approaching Propane Code revision deadline. T&S was directed by the Board to process the proposal with the intention of later formally commenting on the submittal with several specified refinements. Subsequently, most of the Board's desired elements became a part of the OPD program.

It should also be noted that at the New Orleans Board meeting, it became apparent that the question of whether or not the propane industry should continue to work on the OPD concept was irrelevant. The answer to the question was fittingly expressed by a metaphoric phrase that circulated among meeting attendees; "the train has already left the station!" In other words, the time for the OPD had arrived, ready or not!

"Punching The Ticket"-- Or, Order Restored...

In dealing with the unfolding events of the OPD story, NPGA was able to thwart attempts by other organizations to initiate requirements that were premature. With the impending arrival of OPD's, the association strove to organize implementation of this safety enhancement in the most acceptable, structured and organized manner, by:

Countering an immanent and uncontrolled entry of the OPD into the marketplace, NPGA prevailed in effecting a realistic timetable to enhance safety with the new application. The OPD phase-in schedule was very controversial. Some desired to shorten, and others to extend the dates of implementation. Notwithstanding these differences of opinion, a phase-in schedule was finally resolved.
Standardizing uniform types and designs of service valves for 4# - 40# cylinders was accomplished to assist in reducing any confusion on filling and service connections.
A group was organized to develop a performance standard that applies a specific uniformity for the manufacture and performance of OPD's. A performance standard for an OPD assembly, heretofore non-existent, consisting of a service valve in combination with an OPD device, was published in 1999. Under the auspices of a special accommodation by Underwriters Laboratories, prior to the performance standard's publication, manufacturers were allowed to attach OPD's to listed service valves. Consisting of all components, OPD's are now classified as "listed assemblies".
Requiring the OPD to be a safety back-up, rather than a primary filling device, with uniform identification, marking, a tamperproof feature, and interchangeability for use between the cylinders of different manufacturers, was attained.
The fixed maximum liquid level outage gauge for filling cylinders by the volumetric method was retained, which provides a second method of confirming an OPD's integrity.
Meetings were held between representatives of the LPG industry and the leadership of the weights and measures establishment. Consequently, the OPD's were favorably regarded by the weights and measures officials who were willing to work with marketers and provide assistance on the marking of LPG content when filling OPD equipped cylinders.

Finally, An Ongoing Conclusion...

Throughout this endeavor, NPGA members worked diligently to apply reason in the face of adversity. But, have no misgivings, even though the OPD requirement has been published as text in the NFPA 58 LP-Gas Code, 1998 Edition^¹, the device's universal acceptance will undoubtedly be spasmodic as some states adopt new codes on different time schedules.

Nevertheless, in the interest of safety, the states should be encouraged to follow the precepts of the Code^², which elevates consumer safety to a new and higher level, representing the corporate desire of the industry.

So, there we have it. For years to come, consumers and marketers alike will continue to be affected by the known and expected difficulties which result from perhaps the most significant attempt ever to improve safety in the filling of small propane cylinders. At times, it will be extremely difficult to comply with this requirement. However, the NPGA and the LPG industry can again be proud to have played a part in making propane a safer fuel for all.