Patent GB-1144423-A (GB)
Title: A coupling for pipes or the like and a pipe system comprising such a coupling
IPC: F16L19/04
Filed: 1967-07-21
Abstract: 1,144,423. Cleaning pipes; pipe couplings. AB TETRA PAK. 21 July, 1967 [15 Aug., 1966], No. 33687/67. Headings F2G and F2N. A coupling for pipes or similar conduit fittings which require cleaning or/and sterilizing, e.g. in a system for conveying sterile liquid such as sterilized milk in a dairy. comprises an intermediate sleeve 4 arranged between pipe portions 1 and 2 having adjacent flared ends 3, the sleeve consisting of a rigid sleeve portion 14 and an inner sleeve portion 15 of resilient material providing flexible tongues 5 which sealingly engage the inner surfaces of the flared ends 3, and a flushing chamber 10 surrounding the sleeve 4 and formed by an outer casing 7 and nuts 8 which cause the flared portions 3 to be gripped between bearing portions 18 of the nuts and the sleeve 4, there being passageways 16 formed between the sleeve 4 and the flared ends 3, allowing the passage of cleaning or/and sterilizing fluid from the chamber 10 to the interior 13 of the conduit by way of the flexible tongues 5 which act as one-way valves. In the embodiment of Figs. 1 and 2, the rigid sleeve portion 14 is of sheet metal tubing formed and worked to provide at each end a series of bentover portions (6a, 6b, 6c, 6d &c., Fig. 3, not shown), these portions 6 alternating with cutaway portions which provide the passageways 16. In an alternative embodiment (Fig. 4, not shown), the rigid sleeve portion (14<SP>1</SP>) is a casting providing at each end a series of abutments (6<SP>1</SP>) which are separated by the passageways (16), these abutments engaging the flared portion (3) as in the previous example and the resilient inner sleeve portion (15<SP>1</SP>) being suitably  modified to grip the end of the rigid sleeve portion (14<SP>1</SP>). In a further alternative embodiment (Fig. 5, not shown) a series of abutments (6<SP>11</SP>) is provided at each end of the sleeve (4) by  being formed integrally with the resilient inner sleeve portion (15<SP>11</SP>). As applied to a milk conveying system associated with a sterilizer S, Fig. 6, each of a number of pipe couplings K is  constructed in accordance with one of the embodiments described above and the chambers 10 of these couplings are supplied with detergent via supply and exhaust systems IH, UH, respectively, controlled by valves V2, V3 associated with a supply of detergent D and a collector C, respectively, a further valve V1 being arranged to circulate fluid through the interior 13 of the conduit system via the sterilizer S while a fourth valve V4 is arranged to feed steam or other flushing medium to the supply system IH. In operation, following a shutdown of sterilizer S, detergent is first circulated through the interior of the conduit system by operating valve V1 and the sterilizer pump, then detergent is supplied under pressure by the valve V2 to the chambers 10 of the couplings K and, since valve V3 is at that time shut, the detergent is forced past the flexible tongues 5 into the interior of the conduit system to remove any material lodged between the tongues 5 and the flared ends 3, after which the entire system is flushed with steam by opening valves V3 and V4. The connections I and U leading to and from the chambers 10 are arranged tangentially to these chambers and preferably are offset axially as shown. The resulting spiral circulation of steam around the chambers 10 causes an under-pressure in these chambers so that steam may continue to be circulated while the conveying system is in use, since the greater pressure of the milk being conveyed in the pipes maintains the tongues 5 tightly against the interior surfaces of the flared ends 3, these surfaces being preferably polished. The tubes and rigid parts of the couplings are preferably of stainless steel.