Silane and Other Pyrophoric Gases

Silane is not highly toxic, but it is pyrophoric. The ensuing deflagration can cause severe damage. Silane storage falls into two categories: indoor bunker or outdoor nest.

 

Silane cylinders shall be stored while secured to steel frames in a silane nest or bunker that is external to buildings that are open on three sides and enclosed by a roof; the cylinders shall be secured by means of an open chain link fence. A canopy provided to protect the stored cylinders from the elements shall be ≥12 ft above grade. The nest shall be ≥9 ft from buildings and the fence. A three-sided fence with the fourth wall constituted by a building wall is acceptable. Bunkers shall be approved by the authority having jurisdiction.

 

The objective is to provide ample ventilation and minimize potential blast/fire damage in the event of a leak and deflagration.

 

NFPA 318, Chapters 6-4.1, 4.1.1, 4.1.2, 5.1.1, 5.1.2, 5.3

 

Cylinders in silane-dispensing stations shall be separated by means of a 1/4-inch steel plate extending 3 inches beyond the footprint of the cylinder and from the top of a purge panel, to 12 inches below the cylinder valve. 

 

These specifications reduce the chance of having a deflagration or fire and minimize damage and injuries should such an incident occur. 

 

NFPA 318 Chapter 6-4.3 (b)

 

Mechanical or natural ventilation shall provide 1 cfm/ft2 of storing or dispensing area. Mechanical ventilation, if used, shall be furnished with emergency backup power. 

 

These specifications reduce the chance of having a deflagration or fire and minimize damage and injuries should such an incident occur.

 

NFPA 318 Chapter 6-4.3 (c)

 

Automatic water deluge water spray protection shall be provided in dispensing areas directed at individual cylinders activated by UV/IR detectors. Detection will also activate automatic shutoff valves. 

 

These specifications reduce the chance of having a deflagration or fire and minimize damage and injuries should such an incident occur.

 

UC Practice

 

Remote manual shutoff that can be operated from at least 15 feet from the dispensing area shall be provided. 

 

These specifications reduce the chance of having a deflagration or fire and minimize damage and injuries should such an incident occur.

 

NFPA 318 Chapter 6-4.3 (e)

 

Silane-dispensing areas shall be separated from buildings and fences.

 

These specifications reduce the chance of having a deflagration or fire and minimize damage and injuries should such an incident occur 

 

NFPA 318 Chapter 6-4.3 (a), 5.3 (a)

 

An automated sequential inert gas evacuation/purge shall be provided for silane dispensing equipment. The inert gas is introduced upstream of the first vent or exhaust connection of a gas delivery header. 

 

These specifications reduce the chance of having a deflagration or fire and minimize damage and injuries should such an incident occur.

 

NFPA 318 Chapter 6-4.3 (g)

 

Gas cabinets, if used, shall have only enough room for one cylinder and meet the specifications of SEMI F14-93. 


These specifications reduce the chance of having a deflagration or fire and minimize damage and injuries should such an incident occur. 

 

NFPA 318 Chapter 6-5.1.3

 

An automated sequential inert gas evacuation/purge shall be provided in the gas cabinet with the inert gas introduced upstream of the first vent or exhaust connection of a gas delivery header. 

 

NFPA 318 does not mandate compliance with a SEMI standard, but all other parts are taken from NFPA 318 and are meant to reduce the chance of having a deflagration or fire, and to minimize damage and injuries should such an incident occur. The SEMI standard is cited to ensure that the equipment meets an adequate, generally recognized standard of quality.

 

NFPA 318 Chapter 6-7.2

 

Remote manual shutdown shall be provided from the outside of the gas cabinet. 

 

NFPA 318 does not mandate compliance with a SEMI standard, but all other parts are taken from NFPA 318 and are meant to reduce the chance of having a deflagration or fire, and to minimize damage and injuries should such an incident occur. The SEMI standard is cited to ensure that the equipment meets an adequate, generally recognized standard of quality.

 

UC Practice