Limited-Area, OH1 for Oxygen Cylinder Storage?

5/23/2023

Contractor is proposing using a single head system using IFC 903.3.8 Limited Area Sprinkler Systems to satisfy the sprinkler requirement from IFC 5306.2.2 One-Hour Interior Room.

Oxygen cylinder storage at vet clinic, "120 gal" tanks, total of "1644 cu. ft.".

Section 903.3.8 only allows LH or OH1 hazards. It was originally proposed as EH1, revised to OH1 but has not substantiated with code. OH2 comes up in multiple locations (NFPA 13-19 26.11.1.1, NFPA 400 21.2.10.2).

Is there a special provision, or some other way OH1 is appropriate here?

At this point the only solution appears to be relocating the room to an exterior wall which allows a "single head for cooling", which seems to not require any specific density, or to provide a full building system with OH2 in the oxygen room.

Thanks for helping me sort this out.

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7 Comments

SCHULMAN

5/23/2023 08:34:37 am

Oxygen is flammable, but it is not combustible.
Does that help?
(not looking at code ...)

Paul Pinigis link

5/23/2023 11:38:54 am

Oxygen is NOT flammable or combustible, it is an oxidizer only. It cannot burn, but it can increase the rate (and efficiency) of combustion.

Glenn Berger

5/23/2023 09:32:43 am

Is there only 1 cylinder of O2 in play here? Or are their spare (full) cylinders?

If multiple cylinders, then rated construction and sprinklers would be my recommendation.

I do not like to use the limited-area provisions as that gives no flexibility.

Danial Bartle

5/23/2023 10:10:14 am

Compressed oxygen is considered an oxidizer and 1500 cuft is the MAQ unless the building is fully sprinkled or where stored or used in approved cabinets, gas cabinets, exhausted enclosures, gas rooms, as appropriate for the material. (NFPA 55-20 6.3.1.1). Gas rooms have requirements as well if they are used to increase the MAQ. Sprinklers and/or Gas rooms increase the MAQ 100% each.

Same standard 6.11.2.1 Where sprinkler protection is required, the area in which compressed gases or cryogenic fluids are stored or used shall be protected with a sprinkler system designed to be not less than that required by 11.2.3.1.1 of NFPA 13 for the Ordinary Hazard Group 2 density/area curve.

There are likely other items and things I missed but this is a good starting point in NFPA.

5/23/2023 02:26:56 pm

As an additional note provided from the National Fire Sprinkler Association TechNote that actually came out today:
Chapter 4 of NFPA 13 starts out by requiring sprinklers in all areas of the building, but allows limited-area systems to comply with NFPA 13 rules where installed and permitted by the codes. Any partial or limited area system needs approval by the AHJ but every partial system should meet the definition a sprinkler system (2022 NFPA 13, Section 3.3.216, 2020 NFPA 25, Section 3.6.4) with:

1. Water supply
2. Control valve
3. Waterflow alarm
4. Drain

When the partial system meets the NFPA 13 and NFPA 25 definition above, then NFPA 25 would apply. Identifying and enforcing NFPA 25 on partial systems is difficult, but necessary.

The IBC, starting in the 2015 edition, (Section 903.3.8) lowered the extent of the limited area system with the following criteria:

1. Up to six sprinklers per fire area
2. Only in light or ordinary group 1 hazard fire areas
3. Connected to a wet standpipe or to domestic if capable of demand
4. Valves are indicating and supervised
5. Provide hydraulic calculations for approval

Naj

5/23/2023 11:46:00 am

Let the contractor install safety cabinets with the O2 cylinders in them.

David Toshio Williams

5/23/2023 03:36:51 pm

I just used the NFPA 101, 9.7.2 &9.7.3 limited area system for a LOX maintenance building that had a small (200SF) O2 storage room. I initially was confused about the EH/OH2 criteria in NFPA 13, as it initially pointed me towards 0.3gpm/SF over 2500 SF but it seemed the provision single for 0.15gpm/sf says ANY hazardous area that requires not more than 6 sprinkler heads and to only calculate the room area (200SF).

Limited-Area, OH1 for Oxygen Cylinder Storage?

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