Cal. Code Regs. tit. 17 § 12760

Current through Register 2024 Notice Reg. No. 25, June 21, 2024

Section 12760 - Venting of Horizontal Retorts for Removal of Air

NOTE: The following venting specifications are for discontinuous horizontal retorts not exceeding five and one-half feet inside diameter, and are based on data from tests made with round cans in strap iron trays. There is evidence to indicate that the use of perforated sheet metal trays may necessitate supplementary retort venting or modifications in the stacking of cans.

(a) System A. Venting Through Multiple One-Inch Vents Discharging Directly to the Atmosphere.

(2) Operation. The vent valve shall be wide open when steam is admitted to the retort, and shall remain wide open for at least five minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 225 degrees F, or at least seven minutes to at least 220 degrees F.

(3) If vent pipes are to be extended beyond the valves, the extensions shall be of at least one pipe size larger than the vent pipes entering the retort.

(b) System B. Venting Through the Drain Valve and Through Multiple One-Inch Vents Discharging Directly to the Atmosphere.

(2) In addition, the retort shall be equipped with a drain of not less than three-inch pipe size for retorts up to 15 feet in length or of not less than four-inch pipe size for retorts over 15 feet in length.

NOTE: The drain valve may be either globe or gate type.

(3) Operation. The vent valves and the drain valve shall be wide open when steam is admitted to the retort.

(4) The drain valve shall remain wide open for at least two minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 210 degrees F.

(5) The one-inch vent valves shall remain wide open for at least five minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 220 degrees F.

(6) If vent pipes are to be extended beyond the valves, the extensions shall be of at least one pipe size larger than the vent pipes entering the retort.

NOTE: The drain may be extended beyond the valve with pipe the same size as the valve.

(c) System C. Venting Through Multiple One-Inch Vents Discharging Through a Manifold.

(1) Equipment. A retort shall be equipped with unrestricted one-inch pipes, approximately one foot in length, one for each five feet--or fraction thereof--of retort length, approximately symmetrically placed along the top of the shell, uniformly separated, not more than seven feet apart, and connected into a manifold. There shall be one of the above vents within two and one-half feet of each end of the shell. The manifold shall be of 2 1/2 -inch pipe size for retorts up to 15 feet in length, and of three-inch pipe size for retorts over 15 feet in length. Venting shall be controlled by a vent valve in a pipe leading from, and of a size not smaller than that of the manifold.

(2) Operation. The vent valve shall be wide open when steam is admitted to the retort, and shall remain wide open for at least six minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 225 degrees F or at least eight minutes to at least 220 degrees F.

(3) If the vent valve is connected into a discharge pipe or system for removal of steam from the building, the header shall be sufficiently large so that venting will not be impaired.

(d) System D. Venting Through the Drain Valve and Through Multiple One-Inch Vents Discharging Through a Manifold.

(1) Equipment. A retort shall be equipped with unrestricted one-inch pipes approximately one foot in length, one for each five feet--or fraction thereof--of retort length, approximately symmetrically placed along the top of the shell, uniformly separated, not more than seven feet apart and connected into a manifold. There shall be one of the above vents within two and one-half feet of each end of the shell. The manifold shall be of 2 1/2 -inch pipe size for retorts up to 15 feet in length, and of three-inch pipe size for retorts over 15 feet in length. Venting shall be controlled by a vent valve in a pipe leading from, and of a size not smaller than that of the manifold.

(2) In addition, the retort shall be equipped with a drain of not less than three-inch pipe size or retorts up to 15 feet in length or of not less than four-inch pipe size for retorts over 15 feet in length.

NOTE: The drain valves may be either gate or globe type.

(3) Operation. The vent valve and drain valve shall be wide open when steam is admitted to the retort.

(4) The drain valve shall remain wide open for at least three minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 210 degrees F.

(5) The vent valve shall remain wide open for at least five minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 220 degrees F.

(6) If the vent valve is connected into a discharge pipe or system for removal of steam from the building, the header shall be sufficiently large so that venting will not be impaired.

(e) System E. Venting Through the Water Spreader.

(1) Equipment. The water spreader shall be of not less than 1 1/2 -inch pipe size for retorts less than 15 feet in length, with the water inlet connected through the shell so that the spreader pipes extend in both directions from a tee in the water inlet. The water inlet to which the spreader is connected shall be of not less than two-inch pipe size. The vent pipe shall be of at least two-inch pipe size and shall be connected into the water inlet without any restriction in pipe size.

The water spreader shall be of not less than two-inch pipe size for retorts from 15 to 30 feet in length with the water inlet connected through the shell so that the spreader pipes extend in both directions from a tee in the water inlet. The water inlet to which the spreader is connected shall be of not less than 2 1/2 -inch pipe size. The vent pipe shall be of at least 2 1/2 -inch pipe size and shall be connected into the water inlet without any restrictions in pipe size.

If the water enters at or near one end of the retort the water spreader shall be at least as large as the water inlet.

For retorts over 30 feet in length, the Bureau of Food and Drug Inspections, Cannery Inspection Section, shall be consulted for the proper venting requirements.

(2) The water spreader shall have holes of not less than three-sixteenths-inch diameter distributed uniformly along the length of the spreader pipe, and of sufficient number so that their aggregate area is not less than that of a two-inch pipe (3.34 square inches) for retorts up to 15 feet in length, or not less than that of a 2 1/2 -inch pipe (4.75 square inches) for retorts having lengths of 15 to 30 feet.

(3) Operation. The vent valve shall be wide open when steam is admitted to the retort, and shall remain wide open for at least five minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 225 degrees F; or the vent valve shall remain wide open for at least seven minutes to at least 220 degrees F.

(4) If the vent valve is connected into a discharge pipe or system for removal of steam from the building, the header shall be sufficiently large so that venting will not be impaired.

(5) The following table indicates the minimum number of holes permissible in water spreaders when used for venting:

*Number of Holes in Spreader Pipe*

Drill Size Inches	For 1 1/2 -Inch Pipe Outlet (2.02 Sq. In.)	For 2-Inch Pipe Outlet (3.34 Sq. In.)	For 2 1/2 -Inch Pipe Outlet (4.75 Sq. In.)

³/₁₆	74	121	173
⁷/₃	54	89	127
1/4	42	69	97

(f) System F. Venting Through the Drain Valve and Through the Water Spreader.

(1) Equipment. The water spreader shall be of not less than 1 1/2 -inch pipe size for retorts less than 15 feet in length, with the water inlet connected through the shell so that the spreader pipe extends in both directions from a tee in the water inlet. The water inlet to which the spreader is connected shall be of not less than two-inch pipe size. The vent pipe shall be of at least two-inch pipe size and shall be connected into the water inlet without any restriction in pipe size.

The water spreader shall be of not less then two-inch pipe size for retorts from 15 feet to 30 feet in length with the water inlet connected through the shell so that the spreader pipe extends in both directions from a tee in the water inlet. The water inlet to which the spreader is connected shall be of not less than 2 1/2 -inch pipe size. The vent pipe shall be of at least 2 1/2 -inch pipe size and shall be connected into the water inlet without any restrictions in pipe size.

If the water enters at or near one end of the retort the water spreader shall be of at least the same size as the water inlet.

For retorts over 30 feet in length, the Department of Public Health shall be consulted for the proper venting requirements.

(2) The water spreader shall have holes of not less than three-sixteenths-inch diameter distributed uniformly along the length of the spreader pipe, and of sufficient number so that their aggregate area is not less than that of two-inch pipe (3.34 square inches) for retorts up to 15 feet in length, or not less than that of a 2 1/2 -inch pipe (4.75 square inches) for retorts having lengths of 15 to 30 feet.

NOTE: See table in subsection (e)(5) for number and size of holes required.

(3) In addition, the retort shall be equipped with a drain of not less than three-inch pipe size for retorts up to 15 feet in length or of not less than four-inch pipe size for retorts over 15 feet in length. The drain valve may be either globe or gate type.

(4) Operation. The vent valve and the drain valve shall be wide open when steam is admitted to the retort.

(5) The drain valve shall remain wide open for at least two minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 210 degrees F.

(6) The vent valve shall remain wide open for at least five minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 220 degrees F.

(7) If the vent valve is connected into a discharge pipe or system for removal of steam from the building, the header shall be sufficiently large so that venting will not be impaired.

(g) System G. Venting Through a Single 2 1/2 -Inch Top Center Vent--for Retorts Less Than 15 Feet Long.

(1) Venting may be accomplished by the use of a single 2 1/2 -inch unrestricted vent located at the top of the shell, provided this vent is within two feet of the center of the retort.

(2) Operation. The vent valve shall be wide open when steam is admitted to the retort, and shall remain wide open for at least four minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 220 degrees F.

If the vent valve is connected into a discharge pipe or system for removal of steam from the building, the header shall be sufficiently large so that venting will not be impaired.

(h) System H. Venting Through the Drain Valve and Through a Single 1 1/2 -Inch Top Center Vent for Retorts Less Than 15 Feet Long.

(1) Venting may be accomplished by the use of the drain valve in conjunction with a single unrestricted 1 1/2 -inch vent located at the top of the shell, provided the vent is within two feet of the center of the retort.

(2) In addition, the retort shall be equipped with a drain of not less than four-inch pipe size.

(3) Operation. The vent valve and the drain valve shall be wide open when steam is admitted to the retort.

(4) The drain valve shall remain wide open for at least two minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 210 degrees F.

(5) The vent valve shall remain wide open for at least five minutes after steam is turned on, and until the mercury thermometer on the retort indicates a temperature of at least 220 degrees F.

(6) If the vent valve is connected into a discharge pipe or system for removal of steam from the building, the header shall be sufficiently large so that venting will not be impaired.

Cal. Code Regs. Tit. 17, § 12760