Pumps and Hydraulics, Part 1 (of 2)

by N. Hawkins

DUPLEX OIL PUMPS.

The pattern of pump shown in [Fig. 306], is especially designed for use in connection with hydraulic lifts and cranes, cotton presses, testing machines, hydraulic riveting and punching machines, and hydraulic presses of all kinds. Also for oil pipe lines [(see Table, page 341)], mining purposes, and such services as require the delivery of liquids under heavy pressures.

There are four single acting outside packed plungers, which work into the ends of the water cylinders, the latter having central partitions; each individual valve has its own cover or bonnet. The arrangement of compound steam cylinders is shown. The water valves are easily accessible, and are contained in small chambers, capable of resisting very heavy pressures. The general arrangement shown in the engraving is subject to numerous alterations, according to various requirements, but the general characteristic of four outside packed plungers is in all cases preserved.

Fig. 306.

SPECIAL DUPLEX PUMP.
(Outside packed Plunger Pattern for High Pressure.)

Table.

Steam Cylinders.	Water Plungers.	Stroke.	Capacity in Gallons, per Stroke each Plunger.	Strokes per Minute, each Plunger.
Ins.	Ins.	Ins.
16	5	12	1.02	50 to 100
16	6	12	1.47	50 „ 100
16	7	10	1.66	50 „ 100
16	7	18	3.00	40 „ 80
16	8	12	2.61	50 „ 100
16	8	18	3.91	40 „ 80
16	9	12	3.30	50 „ 100
181⁄2	7	12	2.00	50 „ 100
181⁄2	71⁄2	12	2.30	50 „ 100
181⁄2	8	18	3.91	40 „ 80
181⁄2	9	18	4.95	40 „ 80
181⁄2	10	12	4.08	50 „ 100
181⁄2	10	18	6.12	40 „ 80
20	8	12	2.61	50 „ 100
20	8	18	3.91	40 „ 80
20	9	12	3.30	50 „ 100
20	9	18	4.95	40 „ 80
20	10	12	4.08	50 „ 100
20	10	18	6.12	40 „ 80
Steam Cylinders.	Water Plungers.	Stroke.	Capacity of Both Cylinders, in Gallons, per Minute.	Steam Pipe.
Ins.	Ins.	Ins.		Ins.
16	5	12	102 to 204	21⁄2
16	6	12	147 „ 294	21⁄2
16	7	10	166 „ 332	21⁄2
16	7	18	240 „ 480	21⁄2
16	8	12	261 „ 522	21⁄2
16	8	18	312 „ 625	21⁄2
16	9	12	330 „ 660	21⁄2
181⁄2	7	12	200 „ 400	3
181⁄2	71⁄2	12	230 „ 460	3
181⁄2	8	18	312 „ 625	3
181⁄2	9	18	396 „ 702	3
181⁄2	10	12	408 „ 816	3
181⁄2	10	18	490 „ 980	3
20	8	12	261 „ 522	4
20	8	18	312 „ 625	4
20	9	12	330 „ 660	4
20	9	18	396 „ 792	4
20	10	12	408 „ 816	4
20	10	18	490 „ 980	4
Steam Cylinders.	Water Plungers.	Stroke.	Exhaust Pipe.	Suction Pipe.
Ins.	Ins.	Ins.	Ins.	Ins.
16	5	12	3	4
16	6	12	3	5
16	7	10	3	6
16	7	18	3	7
16	8	12	3	7
16	8	18	3	8
16	9	12	3	8
181⁄2	7	12	31⁄2	6
181⁄2	71⁄2	12	31⁄2	6
181⁄2	8	18	31⁄2	8
181⁄2	9	18	31⁄2	8
181⁄2	10	12	31⁄2	10
181⁄2	10	18	31⁄2	10
20	8	12	5	7
20	8	18	5	8
20	9	12	5	8
20	9	18	5	8
20	10	12	5	10
20	10	18	5	10
Steam Cylinders.	Water Plungers.	Stroke.	Discharge Pipe.	Water Press. Pump End will stand, in lbs., per square inch.
Ins.	Ins.	Ins.	Ins.
16	5	12	3	450
16	6	12	4	450
16	7	10	5	300
16	7	18	6	450
16	8	12	6	300
16	8	18	7	450
16	9	12	7	250
181⁄2	7	12	5	250
181⁄2	71⁄2	12	5	300
181⁄2	8	18	7	450
181⁄2	9	18	7	250
181⁄2	10	12	8	250
181⁄2	10	18	8	250
20	8	12	6	450
20	8	18	7	450
20	9	12	7	250
20	9	18	7	250
20	10	12	8	250
20	10	18	8	250

A test of the superiority of this method of moving, and controlling long columns of fluids under extreme heavy pressures was made at the time of the introduction of long pipe lines for conveying oil from the wells to the seaboard.

Note.—After trying various kinds of pumps for forcing the oil through these long pipes, and after having a succession of disasters in the way of burst pipes, and leaking joints, it was decided to test the efficiency of the direct-acting duplex steam pump. These pumps were placed in the various stations along the pipe lines, and after a continued service of many years, have shown their perfect adaptation to that exceptionally hard service. These pumps convey the oil over mountains where at times the coupled lines have been over one hundred miles long between the pumps, and where the pressure on the plunger of the pump sometimes rises to 1,500 lbs. per square inch.

J. F. Holloway.

Fig. 307.

COMPOUND DUPLEX PUMPS.
(With The Deane Switch Valve.)

The application of this valve is shown in [Fig. 307], on the opposite page. It can be attached to any regular Compound or Triple Expansion Pump, and if not in use does not in any way impede the regular running of the machine.

The Deane switch valve is a device by which compound low service pumps may be converted into powerful fire pumps. This appliance consists of a valve of such construction that steam may be allowed to enter the cylinders as usual for compounding, or may be diverted by simply moving a lever, when all four cylinders receive steam at boiler pressure, each exhausting independently to the atmosphere. The change makes each steam cylinder available for its maximum power, all four cylinders develop their full power, and its effect can be utilized in powerful fire streams.

It should be borne in mind in justice to the manufacturers that the Deane switch valve is not to be classed with the ordinary two or four-valve arrangement, which, while admitting initial steam to the second cylinders, develops no power in the first, or, as it is sometimes arranged, uses initial steam in all four cylinders and develops less power than if the second cylinders were used independently.

This valve is recommended by the Insurance companies, and compound duplex pumps fitted with the Deane switch valve will be accepted in place of the Underwriter pump of similar capacity. This valve is also frequently used where two widely differing water pressures are required for other purposes than for fire protection.

Every machine is subject to rigorous tests before leaving the factory, including a 300-pound test of the water cylinders. Every pump is guaranteed to be in full accordance with the specifications.