US2274869A - Sampling device for tanks - Google Patents

Description

March 3, 1942.

w. PFEIFFER SAMPLING DEVICE FOR TANKS Filed April 13, 1940 Patented Mar. 3, 1942 SAMPLING DEVICE. FOR TANKS Walter Pfeifier, Huntington Park, .CalitZ, assignor to Frank V. Long, doing business as The Vapor Recovery Systems Company, Compton, Calif;-

Applieation April 13, 1940, Serial No. 329,489

3 claims.

This invention relates to a sampling device particularly useful for taking samples of a liquid from a tank which is under pressure. While this device can be used with any apparatus enabling it to be introduced through the roof or cover of a tank, it is intended particularly to cooperate with the apparatus disclosed in my copending application, Serial Number 327,242, filed April 1, 1940.

A principal object of the present invention is to provide a container so constructed that it can be controlled from above by suspending means or a line, in such a way as to enable a sample of the -liquid such as oil, gasoline, or anyother industrial liquid, to be taken at any desired level in the tank.

A further object of the invention is to provide a sampling device for this purpose, which is so constructed that if desired, a sample can be taken from a point near the bottom of the tank.

A further object of the invention is to produce a sampling device for this purpose, which will be pressure-tight so that it will retain any gases or vapors passing off from he liquid taken in by the sampling device.

A further object of the invention is to provide a sample-taking device which iscapable of taking a sample from a point above the bottom, and another sample from a higher level in substantially one operation.

Further objects of the invention will appear hereinafter.

The invention consists in the novel parts and combination of parts to be described hereinafter,

all of which contribute to produce an efficient sampling device for tanks.

A preferred embodiment of the invention .is described in the following specification, while the broad scope of the invention is pointed out in the appended claims.

In the drawing Fig. 1 is a vertical section through a sampletaking device embodying my invention. This View shows the preferred construction of the device, which enables it to be used to take a sample at the bottom of the tank, or at any desired depth or level within the liquid.

Fig. 2 is a view similar to Fig. l, but illustrating only the upper portion of the sample-taking device. takes a sample at an elevated level the liquid, in an open position.

Fig. 3 is a vertical section illustrating the parts at the bottom of the sampling device, in their open position.

This view also illustrates the valve that 1 structed so that :it can'be attached toa hook 9 wall of the valve chamber 2.

Fig. 4 is a vertical :section through the thermometer well, and showing afragment 'of the wallof the container at the shoulder Where the thermometer is carried.

.In practicing the invention, I provide a container l which preferably consists of asubstantially cylindrical body-or shell, the upper end of which is formed with a valve chambers at which a valve is located. This container is suspended by means of 'a suspendingmemberor line'3. This container l is intended to be lowered into the tank by 'means of the suspending member 3. I provide means controlled *by the suspending member "3 for efiectingthe opening of thevalve when thesampling device zisllocat-ed :at :any desired level. Any suitable'me'ans may be'provided for this purpose, but in the, present instance I prefer to provide a Valve such as the vmv'e 4, which is a self-closing valve, said valve being mounted so that it may .close an upper'inlet 5 in the-vertical container wall .6 that forms .a side In the present instance, the valve "d is of poppet type and normally held closed by a =.c.oil spring "7, that is, it

is a self -closing valve.

Thevalve is openedat will ithroug-l'iithe agency of avalve opener 8, which :is preferably in the form of aslide, the upper end of whichis conindicated in dotted lines in Fig. 1. This slide, or shoe .8,'is mounted at'the upper end of the container for vertical movement, and in order 'to accomplish this the lower end of the shoe "8 is formed with a longitudinal slot ill through which passes a cross pin H which connects two upwardlyjprojecting posts .52 integral'with the upper end of the container, and spaced apart so as to operate .asguides for the valve opener or shoe "8. The outer face'of the shoe 8 is guided on four guide rollers such as the rollers 11:3 indicated in Fig. 1, :said rollers being carried on horizonta cross pins it connecting the :posts 42.

The lower end of the shoe -8 is formedwith an inclined cam face 55,:and just above the upper end :of this face a roller is carried :by the inner end of'the'valve, rests in aseat so that ashoul- 'der =5? is located just below this roller. The construction :of this operating connectien between the cam and the valve 'is such that the weight 7 will open the valve to its full open position, as indicated in Fig. 2.

The valve 4 is preferably carried and guided on a removable valve plate or cover I8 having a flange or head at its outer end, that seats in a recess I9 formed in the side wall of the body I; and in order to insure that this plate will he gastight, I prefer to provide a gasket 20 under it, which will make a gas-tight connection when the machine screws 2| are tightened up.

This sampling device is preferably constructed so that it can also take a sample from a point near the bottom of the tank, and also so that its interior can be vented to the outside. The means for this purpose will now be described, and it includes a bottom valve 22 which is also a selfclosing valve, being normally held down so as to close the bottom inlet 23, by means of a coil spring 24, the inner end of the spring seating against a washer 25 that rests upon the lower end of a valve stem guide 2'6 that may be made integral with the bottom 2'! of the container. The lower end of the device is preferably provided with extensions 28 below the bottom wall, which operate as contact points for supporting the sampling device on the bottom of the tank when the valve 22 is open, to take a sample from a point slightly above the bottom. Suitable means is provided for effecting the opening of the valve by contact with the tank bottom, and in the present instance, this is accomplished in a very simple manner by having the valve stem 29 extend down slightly below the tips of the extensions or legs 28 (see Fig. 1). With this construction, it will be evident that when the tip of the valve stem 29 strikes the bottom of the tank represented by the line 30 in Fig. 3, the valve will be raised to its open position. In some cases the sampling device may be constructed merely with a bottom valve and no upper valve, in which case the stem 29 should project a considerable distance so as to provide for the quick development of the relatively large effective valve opening. However, in some cases, it may be desired to take a sample from the bottom valve, and while the sampler is being raised, to open the upper valve 4 and take a sample at an elevated point. In doing this, the sample may be held at a fixed level, or it can be pulled upwardly at a predetermined rate sufiicient to enable the chamber 3| in the body, to become substantially full when the sampler arrives at the surface of the liquid in the tank.

The device is provided with a tubular stem or stand-pipe 32, the lower end of which is secured in the bottom 21. The upper end of this tube communicates with the interior of the chamber 3| at a high level, and under the bottom 27 a valve or cook 33 is provided, which is closed when the sample is taken, but which is capable of opening communication from the interior of the stand-pipe to the exterior. When a sample taken not under pressure is being drawn out of the sampler, this valve should be cracked open by means of its handle or lever 34-. This permits air to enter by the tube 32. At this time the sample is drained off through another valve or cook 35 which is also held in its closed position when the sample is being taken, and which can be opened at will by means of its lever or handle 36.

In using the sampler in normal operation, the valves 33 and 35 are closed; that is to say, they are closed when the sample is being taken. The device is submerged in the liquid and is then given a jerk which causes the cam 8 to force the valve 4 to its open position. The liquid will then flow in past the valve 4 while any air or gas in the interior of the device finds its way out past the valve. After a lapse of sufficient time the operator will assume that the sample or bomb is full, and he will then give the supporting cord or wire another jerk. Immediately after the tension of the jerk ceases, by giving slack to the line, the cam 8 will drop down to its normal position indicated in Figure 1, which permits the valve 4 to close. The device can now be removed from the tank. The only vapor within the sampler or bomb would have very little volume, possibly less than one cubic inch, which would .be occasioned by the small space or chamber in the casing above the valve 4.

When the sample is taken under pressure, the sampler is usually sent to a laboratory. The removal of the products is accomplished substantially as follows: First, for ordinary products not under pressure, the valve 33 is cracked so as to permit atmospheric air to enter the air space above the level of the liquid in the sampler as the liquid runs out through the valve 35. Second, where the sample has been taken under pressure, the valve 33 is connected to the apparatus in which the sample is to be tested, and a water line is then connected to the valve 35. Water is then admitted slowly, thereby enabling the sample (which is of an oily nature) to float up on the water and pass out of the tube 32 as the oil rises to the level of its mouth.

In either of these two methods just described, the liquid may be withdrawn from the sampler in a gas-tight manner without evaporation, so that the sample taken will not be subjected to evaporation, and is therefore a true sample.

The valve chamber 2 is of less width than the diameter of the body I, so that a shoulder and a partial transverse wall 31 is formed, which affords opportunity for carrying a thermometer 38 for indicating the temperature of the sample which, of course, is substantially the same as the liquid in the tank, if the operator of the device allows sufficient time for the thermometer to assume the temperature of the sample. This thermometer is carried in a tubular thermometer well 39, secured in place by a bushing 40 screwed into a boss 4! projecting upwardly from the wall 31 (see Fig. 4) and the upper end of the thermometer is encased in a removable screw cap 42 that screws onto the threads at the upper end of the bushing. The upper end of the bushing is preferably provided with a beveled mouth 43 so that when the cap 42 is unscrewed, no mercury 44 from the interior of the well 39 will be lost. This mercury 44 is carried in the well in the usual way, to assist in conducting the temperature of the liquid to the thermometer bulb 45. A curved guard 45 is provided that is attached to the body and projecting over to a point near the upper end of the shoe 8, to protect the shoe.

After the sampling device is pulled out of the tank, the shoe should be pressed down soas to permit the spring I to close the valve 4.

Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.

What I claim is:

1. In a device for taking a sample of liquid from a tank not under pressure, the combination of a container with an inlet for the liquid, a selfclosing valve for closing the inlet, means for suspending the container while lowering the same into the tank, means controlled by the suspending means for opening the valve to take the sample, a stand-pipe secured in the bottom of the container communicating with the interior of the container at an elevated point in the container, and a valve on the outside of the container communicating with the interior of the standpipe for admitting air or gas to the interior when the liquid sample is being drawn from the container.

2. In a device for taking a sample of liquid from a tank under pressure, the combination of a container with an inlet for the liquid, a movable part mounted on the container, a self-closing valve distinct from the movable part, for closing the inlet, suspending means connected to the movable part for suspendin and lowering the container into the tank, said movable part having a cam face with a shoulder normally seating against a part of the valve for opening the valve, said shoulder operating to afiord sufficient resistance to enable the suspending means to support the container without opening'the valve, said cam operating upon a'jerk of the suspending means, to open the valve. v

3. In a device for taking a sample of liquid from a tank under pressure, the combination of a container with an inlet for the liquid, a movable part having a cam, means for guiding thesame to move in a substantially vertical direction on the container, a self-closing valve guidedon the container to move in a substantially horizontal direction and having a part engaging the cam to enable the valve to be opened by the cam, the connection between the cam and the valve including a shoulder on the cam affordin resistance sufiicient to enable thesuspending mean to support the container without opening the valve, and operating upon a jerk of the suspending means, to open the valve, said movable part operating after thejerk, and when given slack, to descend to its original position to permit the valve to close.

. WALTER. PFEIFFER.

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