1999 MAY - Laserfiche WebLink

20.24.120 contents of the single tank or [v] Constructed of steel cylinder of gas which presents with a thickness not less than the highest potential hazard. 12-gauge. [v] Systems utilized for such processing shall be de- signed as a treatment system, as described in subsection (e)3 of this section. If a total contain- ment system is utilized, the system shall be designed to handle the maximum anticipated pressure of release to the system when the system reaches equi- librium. (2) Gas Cabinets. When gas cabinets are provided they shall be: [i] Operated at negative pressure in relation to the sur- rounding area. [ii] Provided with self- closing limited access ports or fire-rated windows to give ac- cess to equipment controls. The average velocity of ventilation at the face of access ports or windows shall be not less than 200 feet per minute (fpm) with a minimum of 150 fpm at any other point of the access port or window. [iii] Connected to a treat- ment system. (3) Treatment Systems. [i] Treatment systems shall be utilized to process all ex- haust ventilation to be dis- charged from gas cabinets, exhausted enclosures or separate storage rooms. Treatment sys- tems shall be designed to reduce the maximum allowable dis- charge concentration of the gas to one-half IDLH at the point of discharge to the atmosphere as specified in subsections (e)5 and 6 below. [ii] When more than one gas may be emitted to the treat- ment system, the treatment system shall be designed to handle the worst case release based on the release rate, the quantity and the IDLH for all the gases stored or used. (4) Treatment System Sizing. Treatment system shall be sized to process the worst case release of each gas based on the maximum flow rate of release from the cylin- der or tank utilized which presents the highest potential hazard. The entire contents of tanks and cylin- ders shall be considered. [iv] Provided with self- (5) Stationary Tanks. closing doors. 710_27 (Pleasanton 5-99)