US321637A - Natural-gas conductor - Google Patents

Description

(No Model.)

J. N. PBW.

NATURAL GAS CONDUCTOR No. 321,637. Patented Juy 7, 1885.

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ihvrrno Srnrns Parenti @reina JOSEPH N. PEW, OF PITTSBRG, PENNSYLVANIA,

NATURAL-GAS CONDUCTOR.

SPECIFICATION forming part of Letters Patent No. 321,637, dated July 7, 1885.

Application flcd February Q4, 1885.

fo @ZZ whom, t muy concern:

Be it known that I, Josnrn N. Paw, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in NaturalGas Conductors; and I do hereby declare the following to be a full, clear, and exact description thereof.

Serious difficulty has been experienced in the conduction and distribution of natural gas, owing to the low temperature and high pressure at which it cornes from the wells. The temperature is about 42 Fahrenheit, and the pressure in the neighborhood ol' two hundred pounds to the square inch. The effect of the low temperature is to contract the pipes, and where they are exposed to the temperature of the atmosphere, it' the latter be higher, an expansion will tal-:e place, so that there is a constant expansion and contraction going on in the pipes, which tend to loosen the joints and cause them to leak. 'This leakage, owing to the highly'explosive and extremely dangerous nature ofthe gas, is a very serious detri As the escape of the gas hasl been the cause of many serious explosions involving destruction of property and loss ot' life, attempts have been made to obviate the con traction and expansion of the pipes by burying them deep enough inthe ground to be below the effect of the changes of temperature at the surface, the theory being that the pipes would then remain at the temperature of the gas at all times; but I have discovered that changes in the temperature are caused hy the reduction of pressure in the pipes, owing to the greater or less demands upon them by the users of the gas, and that to maintain them at a uniform temperature it isnecessary that the pressure also remains uniform. This is impossible, owing to the fac-t that during the day-time there is usually a much greater demand than during the night. and as the pipes are drawn on and the gas therein is more or less exhausted and reduced in pressure its eX- pansion therein produces a reduction of ternperature, which causes a constant expansion and contraction of the pipes, however deep they may he buried. It has been customary to lay these pipes through the streets below (No model the. water and gas mains and service-pipes, so that leakage therefrom in ascending through the ground encounters the water and-gas service-pi pes which lead into the cellars and basements of buildings. There is always more or less space around a scrvicepipe, and the gas encountering` them will follow` such pipes, passing along these spaces, and enters the cellars and basements ol` buildings and collects there, and in many cases explodes with disastrous results. f

Various provisions have been made for the purpose of carrying oif theleakage from natural-gas mains, and stand-pipes leading up from a box or a layer of gravel or broken stone surrounding each joint and discharging the same in the open air have been used. These things, however, have not proven to be entirely eflioaeious, as more or less leakage will seek the channels before mentioned around the servicepipes and enter adjacent buildings. Where the gas-pipes are situate above the surface of the ground 1n uch of the danger of explosion is averted; but this is impracticable in the streets of towns and cities.

rIhe object of my improvementisto increase the safety of the conduction and distribution of natural gas, and, broadly stated, it consists in laying the pipes in a suitable trench at the surface of the ground, and above the water, illumi netting-gas, and other distributing pipes, which trench is covered throughout its entire length by a ventilating-cap provided with slots or holes for permitting the escape of the leakage gas into the open air, where., having no opportunity to collect, it is practically harmless. I prefer to provide my mains and pipes with expansion-joints,which will permit of the expansion and contraction of the pipes without danger of disrupting any part and causing -a leak.

To enable others skilled in the art to make and use my invention, I will now describe it by reference to the accompanying drawings, in which- Figure l is a longitudinal section of the trench, showing the pipe and the means of supporting the saine therein. Fig. 2 is av cross-section on the line .r x of Fig. 1.

Like letters of reference indicate like parts.

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I form a shallow trench, a, in the bottom of which, at suitable intervals-say about eight feet apart-I lay erossti1nbers I), of hard wood, such as oak or other suitable material. The sides of the trench are lined with timbers c, which preferably break Y joint with each other, so as to make a stronger structure, and on top of said timbers are cross-timbers d. The timbers b and d and the intermediate side timbers, c, are'fastened together by vertical bolts e. On top of or between the timbers d, I lay a suitable flooring of boards or iron casings,f, which may be on a'level with the surface of the street or slightly below the same, so as to permit the top to be paved over like the rest of the street. In the top f is a conti mious line of holes orventopenings, g,which are designed to permit the escape of theleakage gas from the trench. In case the top is paved over provision should be made forleaving these openings free, which may be done by making them through a raised rib or a se ries of short tubes, f/,which will eomeup flush with the surface of the pavement. In ordinary weather there will be no difficulty in keeping the openings g clear, and-if in the winter they should become clogged with ice, snow, or dirt, they can be opened by the insertion of a pick or other pointed instrument. The trench a can be drained of water at suitable intervals by pipes or conduits leading to the proper place of discharge, and, if desired, steam or heated air may be blown through the trench by any known or suitable arrangement for that purpose, not necessary here to be described. The gaspipes h are laid in the trench, being supported in proper alignment by supports b on the cross-timbers I), and the sides are of sufficient height to bring the upper cross-timbers, d, above the top of thepipes. As stated, I prefer to provide the pipe 7i with expansionjoints.

I do not limit myself or claim the construction of any particular form of expansion-joint in this case, but design to use any of the known forms suitable to the purpose, one of which is shown at t' in Fig. l.

Vhile I have described and hereinafter claim a preferred form for the construction of the pipe-easing inside of the trench, I do not limit myself to such construction in the use of the features forming the'subj ect-1n atter of other claims.

My improvement provides for the safe and perfect carrying off of the leakage gas and affords an easy access to the pipes for repairs. It gives a cheap and efficient manner of laying the pipes, and obviates all danger of interfering with or injuring the mains and service pipes of other systems of distribution which may be laid in the streets.

As has been shown, it is impossible to prevent the expansion and contraction of the pipes, and I therefore prefer to adopt such means as will obviate danger to thejoints from this cause.

Owing to the conduit being at or near the surface, and yet protected by being situate below the level ofthe street, interference with travel and danger of breakage is averted, and at the same time, owing to the continuous vents, the gas is not allowed to accumulate in a confined space, so as to lead to the danger of expiosions.

I am aware that an outer casing situate around the gas-main and having at intervals Ventilating-pipes is not new. I am also aware that such casings formed of wood have been employed in connection with telegraph-wires, and I do not desire to claim, broadly, any of these features, as the important features of my invention are a conduit for gas-pipes, said conduit having continuous vents and situate at but below the level of the surface of the ground, so as to enable the escaping gas to have free access to the open air, and thereby obviate the danger of the gas collecting and passing through an inclosed space. These vents should be within a short distance of each other, evenlydistributed th roughout thelength of the casing, and so numerous that one or more shall be located within a few inches of the point in the case nearest each pipe-joint, so that no opportunity shall be aorded for the collection of escaping gas.

What I claim as myinvention, and desire to secure by Letters Iatent, is-

l. An improvement in the art of conducting and distributing natural gas, which consists in a gas pipe or main placed in a case or trench at or immediately below the surface, which trench is vented continuously throughout its length, substantially as and for the purposes described.

2. A natural-gas pipe, case, or trench at or immediately below the surface,having its sides lined with strong timbers connected by top and bottom cross-timbers and provided with a continuously-vented surface-cover, in combination with a gas-pipe,substantially as and for the purposes described.

In testimony whereof I have hereunto set my hand this 10th day of February, A. D. 1885.

Josnrrr N. ruw.

Vitnesses:

W'. BCORWIN, THOMAS B. KERR.

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