California Code of Regulations › Title 8 - Industrial Relations › Division 1 - Department of Industrial Relations › Chapter 4 - Division of Industrial Safety › Subchapter 7 - General Industry Safety Orders › Group 20 - Flammable Liquids, Gases and Vapors › Article 136 - Dip Tanks › Section 5426 - Construction of Dip Tanks

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
NOTE: Closed system quench tanks of integral quench
						  furnaces are not included in this Article.
(a) Dip tanks, including drain boards if
						provided, shall be constructed of substantial noncombustible material, and
						their supports shall be of steel, reinforced concrete or masonry, or equivalent
						fire resistant material.
NOTE: Where dip tanks extend through a floor to the
						  story below or where the weakening of the tank supports by fire may result in
						  the tank collapse, supports should be of material having not less than one-hour
						  fire resistance.
(b) Dip
						tanks of over 150 gallons in capacity or 10 square feet in liquid surface area
						shall be equipped with a properly trapped overflow pipe leading to a safe
						location outside buildings.
(c)
						Overflow pipes shall be of sufficient capacity to overflow the maximum delivery
						of dip tank liquid fill pipes but shall not be less than 3 inches in diameter
						and shall be increased in size depending upon the area of the liquid surface
						and the length and pitch of pipe.
(d) If the liquid surface area of dip tank
						(and drain board, unless drain board is arranged to positively prevent drainage
						into dip tank) is 75-150 square feet, diameter of overflow pipe shall be not
						less than 4 inches; if 150-225 square feet, not less than 5 inches; if 225-325
						square feet, not less than 6 inches.
NOTE: 1. On large dip tanks, multiple overflow
						  connections are preferable to a single large pipe, provided the aggregate cross
						  sectional area is equivalent.
NOTE: 2. Overflow pipes should be connected to dip
						  tanks through a flared outlet where the accumulation of caked or dried material
						  may clog the overflow opening.
(e) Piping connections on drains and overflow
						lines shall be designed so as to permit ready access for inspection and
						cleaning of interior.
(f) The
						bottom of the overflow connection shall be not less than 6 inches below the top
						of the tank.
(g) Dip tanks over 500
						gallons in liquid capacity shall be equipped with bottom drains automatically
						and manually arranged to quickly drain tank in event of fire, unless the
						viscosity of the liquid at ambient temperature makes this impractical. Manual
						operation shall be from a safely accessible location. Where gravity flow is not
						practicable, automatic pumps shall be required.
(h) Such drain shall be trapped and discharge
						to a closed properly vented salvage tank or to a safe location outside which
						will not endanger property.
(i)
						According to tank capacity the diameter of bottom drain pipe shall be not less
						than the following:
500 to 750 gallons--
3 in.
750 to 1,000 gallons--
4
								  in.
1,000 to 2,500 gallons--
5
								  in.
2,500 to 4,000 gallons--
6
								  in.
over 4,000 gallons--
8 in.
(j) Where the drain line is long or of poor
						pitch the pipe size shall be increased to at least the next larger
						size.
1.
						  Amendment of subsection (b) filed 7-8-85; effective thirtieth day thereafter
						  (Register 85, No. 28).
2. Amendment file 12-5-86; effective
						  thirtieth day thereafter (Register 86, No. 51).
Note: Authority cited: Section
							 142.3, Labor
							 Code. Reference: Section
							 142.3, Labor
							 Code.