Fiberglass Tank in Hydrocarbon Service

[RRE]

Would appreciate a steer on the use of fiberglass storage tanks in natural gas service. Background: we produce natural gas, oil condensate (light oils of API gravity 50-70), and lots of produced water. Typically, the gas patch industry uses steel tanks to store the separated oil condensate in steel tanks and the produced water in fiberglass tanks. The problem is that separation is often not 100% efficient or during upsets, there is condensate that goes into the produced water tanks (FRP). API 12P leaves the burden to the user and does not provide guidelines for not using FRP for this type service. I am aware that fire codes (as well as OSHA 1910) prevents the use of FRP in if hydrocarbon is present. Any opinions on what you do in this same service?? Any other codes I can refer to that would assist me in using steel tanks in this service rather than fiberglass?

Also posted in the API forum.

 

[MJCronin]

RRE..

Have you checked NFPA-30 ???

I believe that there is a restriction against using non-steel tanks in flammable service ?

Consider re-posting this question in an NFPA forum or at

http://www.ast-forum.com.

After you have found an answer, come back later and complete this thread

Regards,

-MJC

 

[RRE]

After some searching, I found the following guidance on my question. Although lengthy, will include for completeness.

Bottom line, OSHA does NOT permit the storage of Class 1 and 2 liquids that are flammable or combustible. Note that there is a distinction between aboveground and belowground FRP usage also.

You may read further on this is in:

http://www.ast-forum.com

Letters to OSHA in 1978, 1991, and 1993 helped clarify OSHA's position and are included below:

October 2, 1978
MEMORANDUM FOR: VERNON A. STRAHM
Regional Administrator Kansas City, Missouri

THRU: DONALD E. MACKENZIE Field Coordinator

FROM: BRUCE HILLENBRAND Acting Director, Federal Compliance and State Programs

SUBJECT: 29 CFR 1910.106 - the use of fiberglass tanks for storage of crude oil.

Any requirement or condition that is in compliance with the latest NFPA Code, which has no lessening effect on the safety and health of the employees, substantially, meets the intent of the Act and OSHA's program directive #200-67. Fiberglass tanks used for the storage of crude oil at isolated wellheads are acceptable to OSHA because they are located in areas completely isolated from other structures and there is little employee exposure to the tank. It is unnecessary to require compliance with more rigid standards for such isolated storage tanks. Any violation of the present OSHA standards for fiberglass storage tanks located at isolated wellheads will be considered de minimis.

The memorandum dated February 11, 1977, incorrectly stated that Class III B liquid in other than isolated rural areas would have to meet other requirements and is best handled through the variance route. At the present time OSHA standards do not provide regulations for Class III B liquids. However, fiberglass storage tanks used for storing Class III A to Class I liquids is permitted at isolation wellheads.

September 9, 1991
Mr. Glen B. White
Scientific Information Services
4820 Highway, 377 South
Post Office Box 122075
Fort Worth, Texas 76116
Dear Mr. White:
This is in further response to your letter of July 20, concerning the storage of flammable and/or combustible materials in fiberglass reinforced plastic (FRP) tanks.
You referenced the Occupational Safety and Health Administration (OSHA) standard at 1910.106(b)(1)(i)(a) with respect to the definition of "noncombustible construction" of storage tanks. You inquired if FRP containers that are designed for underground storage of flammable and/or combustible materials could be used for aboveground and indoor storage.
OSHA defines noncombustible materials as those materials which are not capable of burning or igniting. Since FRP is capable of burning in the presence of a flame, OSHA considers such material to be combustible, and usage of such material in constructing storage tanks for flammable or combustible liquids to be located aboveground or inside buildings will be in violation of 1910.106(b)(1)(i)(b).
The exemption provided in 1910.106(b)(1)(iii)(b) for tanks designed for underground service with capacities less than 2500 gallons, which are allowed to be used for aboveground service, does not apply to tanks that are built of combustible materials.
Thank you for your interest in safety and health of employees. If we may be of further assistance, please contact us.

Sincerely,
Gerard F. Scannell
Assistant Secretary

January 13, 1993
Mr. James L. Jones, III, ARM
Training Manager
Ennis, Lumsden, Boylston & Associates, Inc.
605 Eastowne Drive
Chapel Hill, North Carolina 27514
Dear Mr. Jones:
This is in response to your letter of December 1, concerning whether the use of fiberglass tanks for above and below ground storage of flammable and combustible liquids, from gasoline to asphalt, meets the intention of the Occupational Safety and Health Administration's (OSHA) 29 CFR 1910.106(b)(1), Flammable and Combustible Liquids standard.
Fiberglass storage tanks, as described in your letter, meet the intent of our 1910.106(b)(1) standard only if their use is restricted to installation underground, or required by the properties of the liquids stored, or used for the aboveground storage of Class IIIB liquids. Fiberglass is considered to be a combustible material due to the flammability of the polyester resin used as a binder for the glass, and thus its use as a type of tank for aboveground storage of Class I, II and IIIA flammable and combustible liquids would be prohibited under OSHA's 1910.106(b)(1) standard.
As you may be aware, OSHA does not regulate Class IIIB liquids. OSHA traditionally has accepted the use of aboveground fiberglass tanks for the storage of certain combustible liquids, such as crude oil, if the tanks are installed in isolated rural areas and meet the other requirements of the latest National Fire Protection Association (NFPA) 30 (1990) standard. Combustible petroleum products of the same class as crude oil may also be stored in aboveground fiberglass tanks if the tanks are also located in isolated rural areas.
We hope the information provided above will be of assistance to you.

Sincerely,
Roger A. Clark,
Director
Directorate of Compliance Programs