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NFPA 52 Now Requires Your CNG Station to Have a Maintenance Plan

By Leo Thomason, Executive Director, NGVi

Because of the unique physical properties of natural gas, the distinctive design and construction requirements of CNG fueling stations, and unique CNG station components like dryers, compressors, high-pressure storage, control systems and dispensers  designed specifically to handle pressurized gas, the operation and maintenance practices for CNG stations are very different from those used for liquid fuel stations. To ensure safety at CNG stations, sustain optimum performance, enhance reliability, control operating costs, and ensure environmental and regulatory compliance–performing routine and proactive maintenance on CNG stations is essential.

According to the 2016 version of NFPA 52, CNG fueling stations are now required to have an active, documented maintenance plan. The goals of such a plan include managing maintenance activities, monitoring system operation, providing emergency fueling support when required, enhancing equipment reliability and consistently delivering clean fuel to vehicles. The plan should address every CNG fueling station component and specify the maintenance intervals and  procedures required to keep the equipment safe and operable.

It is important to note that because the code requirements are retroactive, every CNG station–currently operating or yet to be constructed–will now be mandated to have a maintenance plan implemented. Moreover, regardless of whether station maintenance is  conducted by in-house personnel, third party outside contractors, or some combination of both, the code still requires each station  to have a written maintenance plan in place.

Since CNG stations vary based on design, size and performance specifications, their maintenance plans cannot be generically applied and must be designed based on each station’s unique equipment  and operating conditions. Additionally, because CNG station components have to be maintained in accordance with manufacturer instructions, the plan must be in compliance with each specific manufacturer’s equipment.

Before a maintenance plan can be established, it is critical that the station owner understands what the station was designed to deliver and what performance levels are required of the equipment. They should evaluate station performance standards for:

  • Fuel  Delivery  –  usually expressed as the quantity of fuel to be dispensed over a  specified time period, or number of  vehicles to be fueled over a particular time period, or the fueling pressure at a specified temperature. This information helps evaluate whether the station is performing as specified.
  • Gas Quality – specifications for oil content, water content, and odorant level. Since gas quality can significantly affect the performance of the station and fueled vehicles, this information is vital.
  • Operation  and  Maintenance – the amount of time that the station is expected to be operational and when maintenance can be performed.
  • Overall  Operation  and  Maintenance  Costs – total  operating costs for the station, including fuel, maintenance and energy costs. This specification helps determine whether the station is operating within the projected cost limits.
  • Local Service – regardless of whether the station uses a third party maintenance contractor or in-house  personnel, this specification helps determine whether the minimum specifications for service expectations are met.
  • Noise Level –  the minimum specification for noise level, measured in decibels.
  • Liquid and vapor fugitive emissions – a specification which establishes the minimum liquid or vapor fugitive emissions coming from the station’s equipment.

A complete maintenance plan should include manufacturer maintenance and repair guidelines, testing and recertification frequency, diagnostic information and much more. It should clearly define what is to be done, who will do it and when it is to be performed.

Effective CNG station maintenance plays an important role in ensuring the operational health safety and reliability  of the equipment. Since every CNG fueling station, even if maintained by a third-party, is now required by code to have a written  maintenance plan, station owners and everyone involved in implementation and execution of this plan must be fully familiar with the station components and their function. They must understand performance levels of the equipment, and know the maintenance and operating principles of their CNG fueling station(s). Having a full understanding of the station’s functions, specifications and applicable maintenance practices will not only help station owners  more effectively manage in-house and/or third party maintenance personnel, but also assures that the station maintenance plan is fully and properly executed.

To learn more about how to develop the NFPA-52 required plan, sign up for our September Tech Talk entitled Required by Code: The CNG Fueling Station Maintenance Plan or register for our comprehensive CNG Fueling Station Operation and Maintenance Training, available as either an e-learning or instructor-led course.