US2845313A - Apparatus for compressing pump liner packing - Google Patents

Description

y 29, 9 w. J. BENSON ETI'AL 2,845,313

APPARATUS. FOR COMPRESSING uMP LINER PACKING Filed July 5, 1955 INVENTOR. WALTER J. BENSON ROBERT S. LONGWELL ATTORNEY a I II Patented July 29, 1958 ice APPARATUS FOR COMPRESSING PUMP LINER PACKING Walter J. Benson, Miami, Fla., and Robert S. Longwell, Piedmont, Calif.

This invention is related to pumps and is more particularly directed to apparatus for compressing pump liner packing.

In the oil well drilling industry, it is the conventional practice of pumping oil, water or mud from an open pit or tank into the drill pipe during the drilling operation. The mud or other fluids are pumped at pressures of from 2,000 to 2,500 lbs. per sq. inch whereby the fluids are pumped through the drill pipe where they pick up the ground particles of stone, etc. at the rotary bit and flow back up along the outside of the drill pipe to the surface of the ground. In order to maintain such high discharge pressures by the reciprocating slush pumps which are utilized, the packing situated between the cylinder casing and the cylinder liner must be compressed under a force of as much as forty-five tons. At present this force is applied mechanically by the effort of four men to turn the liner stud by the use of a four foot pipe wrench having a six foot pipe extension. It has been found that within approximately two hours of operation of the reciprocating n slush pump, a leakage occurs at the tattle tale relief port, and immediately the liner stud must against be tightened. At least once each day the pump must be dismantled and the packing replaced because of the high rate of leakage. The reciprocating movement of the piston causes the liner likewise to reciprocate, which in turn varies the pressure on the packing and consequently permits a leakage therein.

The present invention contemplates the application of hydraulic pressure against the liner so as to maintain a constant pressure on the packing at all times.

Therefore a principal object of the present invention is to provide hydraulic operated apparatus for compressing a pump liner packing of reciprocating slush pumps for reducing leakage to a minimum.

A further object of the present invention is to provide hydraulic pressure for maintaining a constant force on packing placed about a cylinder liner in a reciprocating slush pump.

A still further object of the present invention is to provide a combination of hydraulic pressure and mechanically applied pressure on a pump liner packing whereby the latter pressure prevents leakage from occuring at the liner packing in the event of a failure of the hydraulic system.

A still further object of the present invention is the provision of a hydraulic system for compressing a pump liner packing described as above which system is readily adaptable to the present reciprocating pumps, is inexpensive to maintain and most eflicient in preventing the occurrences of leakages, thereby resulting in a considerably lowered pump operation cost.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming a part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawing but may be changed or modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure l is a longitudinal cross sectional view of a cylinder head, pump cylinder and sleeve liner assembly embodying my invention.

Figure 2 is an enlarged cross sectional view of the cylinder head.

Figure 3 is an enlarged cross sectional view of a combination check valve and Alemite fitting. v

Referring to the drawing wherein like numerals are used to designate similar parts throughout the several views, the numeral refers generally to a double action pump consisting of a casing 11 forming the cylinder thereof. The casing 11 which is of conventional and well known construction is provided with the usual inlet and outlet ports (not shown) and has a cylinder liner 12 slidably mounted in the cylinder 11. Both the liner 12 and the cylinder 11 are provided with annular shoulders 13 and 14 respectively that are disposed opposite to each other to form a packing chamber 15 in which there is mounted a lantern ring 16 engaging the outer surface of the liner 12 and the inner surface of the cylinder 11. Packing 17 and 18 are placed on either side of the lantern ring 16 in the chamber 15 to complete the seal between the liner 12 and the cylinder 11. A tattle-tale relief port 19 communicates between the packing chamber 15 and the atmosphere permitting the escape of any fluids that leaked past the packing 18 so that a person may be apprised of the fact that a leakage past the packing has taken place.

Within the cylinder liner 12 there is slidably mounted a double acting piston 20 whose rod 21 extends outwardly of the casing 10 through an opening 22 in which a packing gland 23 is mounted. The rod 21 extends through the gland 23 and a cover plate 24 mounted on the casing 11 by studs 25. Packing 26 placed in the gland 23 is maintained in a tightly compressed condition by tightening nuts 27 on the studs which draws an 'annular shoulder 29 of the cover plate 24 tightly against the packing 26 in the gland 23.

The other end of the cylinder casing 11 is sealed by a cylinder head 28 bolted asat 30 to the casing 11 and provided with axially disposed bores 31 and 32. Bore 31 which extends approximately midway of the head 28 is threaded to receive a threaded stud 33 while bore 32 being larger in diameter than bore 31 connects with the latter by means of an annular shoulder 34. The stud 33 extends as at 35 beyond the inner surface of the cylinder head 28 where it bears against a spider or liner cage 36 whose other end is in engagement with the free end of the cylinder liner 12. Within the bore 32 and mounted about the liner stud 35 is a sleeve-like inner cylinder 37 which is provided with a base portion 38 extending outwardly to the side walls of the bore 32 and the shoulder 34. A peripheral slot 39 in the base portion 38 of the inner cylinder 37 receives a rubber seal ring 4% which prevents the flow of fluids from the bore 32 to the bore 31. The remainder of the bore 32 not taken up by the sleeve 37 is occupied by an annular hydraulic ram 41 which is slidably mounted therein. The inner end of the hydraulic ram 41 is provided with a pair of annular slots 42 and 43 in which are received rubber seal rings 44 and 45 respectively forming a sealed chamber 46 in the bore 32 positioned between the hydraulic ram 41 and the base portion 38 of the inner cylinder 37.

Means are provided to communicate with the chamber 46 comprising ducts 47 and 48 whose outer end portions are threaded and which extend through the cylinder head 28 and the base portion 38 of the inner cylinder 37. Threaded in the bore 47 is a body portion of an bore 56 which extends the full length of the Alemite fitting 49 and the valve assembly 50 permits the flow of fluid therethrough into the duct 47. A conventional relief valve fitting or plug 57 containing a relief valve is threadedly mounted at the threaded portion of the duct 48. A lock nut 58 is mounted on the bolt 33 for locking the liner stud 35 in position. With the application of fluid under the desired pressure of approximately 2,000 lbs. per square inch at the Alemite fitting 49, the chamber 46 will become filled with the fluid causing the hydraulic ram 41 to slide outwardly bearing against the liner cage 36. The force exerted thereon is transmitted to the cylinder liner 12 compressing the liner packing 17 and 18 against the lantern ring 16. Now the lock nut 58 is loosened and the liner stud 33 is tightened until the end 35 of the stud 33 bears tightly against the liner cage 36 to maintain the force against the packing 17, 18 in the event of a leakage in the hydraulic system. The lock nut 58 is then tightened to prevent the inadvertent loosening of the liner stud 33 in the threaded bore 31.

As the piston 20 reciprocates in the cylinder liner 12, the friction therebetween tends to cause the liner 12 to reciprocate likewise. However, the hydraulic pressure on the ram 41 maintains a constant pressure at all times on the cylinder liner 12 and thereby prevents the latter from reciprocating.

Leakage at the tattle-tale relief port 19 is effected by the change in pressure on the packing 17 and 18 which is brought about by the reciprocating movement of the cylinder liner 12. Since the hydraulic pressure on the ram 41 prevents the cylinder liner 12 from sliding back and forth as the piston 20 reciprocated therein, the packing 17 and 18 are able to prevent the leakage of fluid thereby.

In the conversion of the reciprocating slush pumps to include the present invention all that need be done is replace the present cylinder heads with the cylinder head 28 shown and described hereinabove.

Having described our invention, what we claim as new is: v

1. In a reciprocating pump having a casing, a cylinder lining slidably mounted in said casing, packing means mounted between said casing and said cylinder lining, the combination comprising a cylinder head mounted on said casing and having a pressure chamber, a ram mounted in said pressure chamber and extending beyond said cylinder head, a liner cage extending between said cylinder liner and said ram, a duct extending through said cylinder head and communicating with said pressure chamber and valve means mounted in said duct for controlling the flow of fiuid through duct.

2. in a reciprocating'pump having a casing, a cylinder lining slidably mounted in said casing, said casing and said cylinder lining having oppositely disposed shoulder means forming a chamber, packing means mounted in said chamber, said chamber having an outlet port, the combination comprising a cylinder head having an inner and outer portion mounted on said casing, a bore extending axially in said cylinder head, said bore being threaded at its outer portion, a liner stud threadedly mounted in said bore and extending beyond the inner portion of said cylinder head, and inner cylinder mounted about said inner portion of said stud, said inner cylinder forming a pressure chamber, a ram slidably mounted in said pressure chamber, a duct extending through said cylinder head and communicating with said pressure chamber, and a valve mounted in said duct.

3. A cylinder head for reciprocating pumps having a bore axially disposed through said head, said bore being threaded at one end and enlarged at the other end, a liner stud threadedly mounted in said one end of said bore and extending through said other end, an inner cylinder mounted about said liner stud at said other end of said bore, said inner cylinder forming a pressure chamber, a ram slidably mounted in said pressure chamber, a duct extending through said cylinder head and communicating with said pressure chamber, and a valve mounted in said duct for controlling the flow of fluid to said pressure chamber.

References Cited in the file of this patent UNITED STATES PATENTS

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