1844.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



191 



so that the concussion was much reduced, while the water way was in- 

 creased J but the latter being all lateral, it was requisite to have a large valve 

 ehaniher. The beats of this valve were formed of tin. Mr. Jenkyii's valve, 

 differed in construction from the one just described, in having the rings con- 

 nected with each other by shackle-joints, instead of their working on a ver- 

 tical spill ; the mode of forming the beat was also peculiar ; it was composed 

 of two thicknesses of leather, between which, wedges of wood were driven, 

 into a groove, cast for their reception in the rings ; these materials were so 

 placed, that the edges of the leather, and the end grain of the wood, might 

 form the striking surface of the beat, after being turned off in the lathe. 



In the third class of valves, which avoided concussion by reducing the ho- 

 rizontal area of the moving parts, were Messrs. Harvey and West's, and Mr. 

 Hosking's double-beat, (See Journal, 1840, vol. iii. page 41 and plate 1,) and 

 Mr. Darlington's cylindrical single-beat valves. The first of these was a 

 modification of the double-beat steam valve, so long used in the Cornish 

 engines ; the second named was similar in principle, and was only slightly 

 different in construction. They were both good valves, each giving large 

 lateral water ways, and therefore they required valve chambers of correspond, 

 ing size, to ensure their perfect action. Mr. Darlington's cyliudiical single- 

 beat valve, was contrived for a large set of pumps under his management, at 

 the Alport Mines (Derbyshire.) The rising column of this pump, was 38 

 inches diameter and 22 fathoms in height ; it was therefore desirable in such 

 a pump, to reduce the concussion, as much as was consistent with the power 

 of closing the valve in proper time ; this was accomplished, by causing a 

 cylinder to rise over a metal-ring packing in the seating of the valve, so 

 much, as to give a large lateral water way under the beat, formed by the 

 bottom of the cylinder. This valve was found to act well, but it required a 

 very large chamber for the water to enter ; the reason for adopting one, in- 

 stead of two beats, was to avoid or lessen the leakage, caused by chips getting 

 between either of the beats. 



The only valve belonging to the fourth class, was that of Messrs. Palmer 

 and Perkins, (See Journal, 1841, vol. iv. p. 335); it consisted of au elliptical 

 disc, moving on an axis placed parallel with, and near to, the minor axis of 

 the ellipse, and closing at a considerable angle, against the interior surface of 

 a cylinder. In a valve so constructed, it would be readily perceived, that the 

 concussion might be reduced to any extent, by bringing the working axis 

 nearer to the geometric axis of the ellipse; because the force with which it 

 closed, must depend on the difference of area, between the upper and lower 

 portions of the disc. It possessed an advantage in the extent and character 

 of its water way, over all the other valves described, nearly the whole of the 

 water-passage being parallel to the side of the pump. On the other hand it 

 was objected, that the axis would be liable to rapid abrasion, and conse- 

 quently the valve would become leaky ; but Mr. Jordan did not concur in the 

 opinion, of that being an insurmountable difliculty, and he hoped that the 

 valve would be tried, under circumstances vihich would put its merits to a 

 severe test. 



Remarks. — Mr. Taylor said, that the subject of valves for pumps, had been 

 so ably treated, by Mr. Homersham, in his paper, (which was read before the 

 Institution last session, (See Journal, 1843, vol. ii. p. 42J,) ) and in the dis- 

 cussion upon it, that there remained but little for him to say. He could not, 

 however, allow the model, which had been exhibited by the permission of 

 Sir Henry De la Beche, to pass without a few remarks. 



In Cornwall, after the improvements in steam-engines had made consider- 

 able progress, attention was directed to the more perfect construction of the 

 pumps. The plunger was introduced aljout that period, and the merit of it 

 has been claimed by different parties;'" its use was attended with many 

 advantages, and had now become almost universal. Some of the benefits 

 derived from its substitution, for the common piston or bucket, had no re- 

 ference to the subject of valves, and therefore need not be mentioned. In 

 one point it was of great importance ; for as the size of the water-way of the 

 valves in the bucket, was necessarily limited by the diameter of the working 

 barrel, an arrangement like that of the plunger pump, which permitted both 

 valves to be fixed in soatings, of which the areas might be increased to any 

 convenient extent, became the more desirable ; it was therefore eutraordinary 

 that such tardiness had been exhibited, in taking advantage of such an ob- 

 vious improvement, when the principle had been long known, and the loss of 

 power, consequent on the former system was admitted. The model which 

 had been explained by Mr. Jordan, showed how much the attention of engi- 

 neers, had now been directed to the subject. In the discussion of Mr. 

 Homersham's paper, Mr. Taylor had mentioned the advantage which had 

 resulted, from the extension of the water-way of some large pump-work, by 

 having two suction-pipes, or wind-bores, and thus doubUng the passage 

 through the valves. It appeared important, for all the valves that discharged 

 the water laterally, that more space should be provided, round the seatings 

 in which they were placed, and for want of that precaution, some excellent 

 valves had not answered so well as they would otherwise have done. That 

 which was invented by Mr. Darlington, to avoid some inconveniences in the 

 use of the double-beat valves, would have been improved by an enlarged 

 space around it. As mines increased in depth, and the volume of water 

 became larger ; as steam-engines came into use, having a rapid and sudden 

 motion, as compared with that of water-wheels, which were formerly univer- 

 sally employed for puiuping, a great inconvenience was felt, from the con- 



13 The plunger was used by Sir S. Morland in 1683, tor the force-pumps at the 

 Machine de Marly. 



cussion in the columns of the pumps ; this was occasioned by the beating of 

 the valves upon their seats, and in pumps, of the diameter needful for drain- 

 ing some of the mines, this evil became very serious. Almost all the im- 

 provements in valves were made with that view; the division of the old 

 butterfly valve into segments was an obvious first step; it had succeeded ex- 

 tremely well, and was still not much excelled. The annular valves of Hos- 

 king, Jenkyn, Simpson '" and others, were based on the admitted principle, 

 of dividing the falhng clacks into several parts, that they should not rise so 

 high, and that they might collapse in succession, and thus avoid concussion. 

 Harvey and West's double-beat valve partook of that principle, but was 

 stated to have the advantage, of presenting a small area, to be acted upon by 

 the pressure of the column of water upon it. Darlington's valve, which was 

 contrived to avoid the inconvenience, arising from the leakage, from both the 

 beats of Harvey and West's valve, when any substance obstructed its perfect 

 doling, presented also a small area for the pressure to act upon ; but as it 

 discharged the water laterally, it required an increased space around the 

 seating. 



The model exhibited a valve, introduced by Messrs. Palmer and Perkins, 

 upon a principle, by which concussion might be considerably reduced, by 

 bringing into action, a part of the superincumbent pressure, to check the 

 descent in closing the orifice. This valve had not yet been tried in large 

 pumps; but the opinions of practical men appeared to be in its favour.' ^ 

 In the construction of all valves, it was of importance, not only to attend to 

 the points which had been mentioned, but also to their durability, and their 

 facility of removal and repair. The actual cost of the valves was of little 

 importance, when compared with the labour and hindrance in removing, or 

 changing them, where the influx of water was great. Serious expense, and 

 loss of time, were frequently occasioned by such stoppages, and the deeper 

 parts of the mines, were exposed to obstructions, which were overcome with 

 great difficulty, notwithstanding many ingenious and well-arranged contriv- 

 ances, to render the process of repair easy and exp^editious. Very powerful 

 capstans and other means were provided for these emergencies, and as the 

 labour of fifty or sixty men was someiimes required to work these machines, 

 it would be easily conceived, how important it was, that such operations 

 should occur as seldom as possible, and that the most perfect and durable 

 construction should be aimed at. 



Mr. Perkins observed, that although at the first view, a certain degree of 

 resemblance might appear to exist, between Belidor's valve and the disc valve 

 of Palmer and Perkins, there existed in reality, but little similarity between 

 them. The former was placed horizontally, whether used as a clack or as a 

 bucket ; in all cases it required to be adjusted to a seating formed of reversed 

 cones, like the ring of a steam throttle valve ; and it was always attached to 

 a packed bucket or piston. Whereas the latter worked at an inclination of 

 about ^ of the diameter of the pump ; it was adjusted within the bored pipe 

 without any seating; and it formed a piston witliout any packing. Its form 

 being that of an oblique section of a solid cyhnder, whose diameter was equal 

 to the interior of the working barrel, and the line of its suspension being 

 beyond the diameter, the areas of the two portions of its surface were un- 

 equal ; consequently, there was more pressure on one side of the line of sus- 

 pension, than on the other. By this extra amount of pressure, the disc was 

 turned on its axis, allowing a free passage for the water, parallel with the 

 sides of the pump. The closing of the lower valve on the return stroke was, 

 for this reason, without noise or concussion. It was evident also, that as 

 packing was not necessary for the disc piston, and as the rubbing surface of 

 its periphery was very small, the friction must be greatly diminished. 

 Messrs. Bramah and Robinson, made an experiment for comparing a pump, 

 with a packed bucket and butterfly valves, with one having a disc piston ; the 

 diameter of both pumps was 10 inches, with a stroke of 8 inches, a lever of 

 six to one, and a lift of water of o feet ; it was found that the former required a 

 force equal to 460 lbs., and the latter 196 lbs to complete a stroke. As re- 

 garded their duration; a disc pump 7 inches diameter, with a .stroke of 8 

 inches, and a lift of 40 feet, drawing its water through 600 feet of suction 

 pipe, rising in that length 28 feet vertically, and worked by a steam engine 

 26 strokes per minute, had been foimd, after working nearly night and day, 

 at the Equitable Gas Works, during fifteen months, without repair, to exhibit 

 but little appearance of wear in the piston, and both it, and the clack valve, 

 were perfectly tight. As the subject appeared to interest the Institution, he 

 promised to present, on a future occasion, a more detailed account of some 

 similar pumps, with the actual results obtained. 



Mr. Lowe corroborated the statement, of the efliciency and duration of the 

 valve, used at the Equitable Gas Works ; its friction was necessarily very 



1 4 The annexed engraving of a treble ring valve, tig. 13, is a section of Mr. Simpson's 

 valve described by Mr. Homersham, in his pa;ier of last session before referred to. It is 

 a conical valve formed of rings, shutting down upon separate seatings, allowing a passage 

 for the water both inside and outside the rings. Valves of this construction have been 

 introduced at the Lambeth and Chelsea water works. The valve at the Lambeth works 

 is 3I> inches diameter, the perpendicular rise or lift when fully open does not exceed 12 

 inches. The clear uninterrupted aiea through which the water passes is more than two 

 thirds of the whole area of the valve, the internal diameter of the scaling being 27 inches. 

 The valve at the Chelsea works is -43^ inches diameter, and the greatest height to which 

 the rings of the valve rise, does exceed '2\ inches. 



15 A valve of a very similar construction is described in Belidor's "Architecture Hy- 

 dralique," vol. iii., p. 2S1, as having been int'-oduced by him in 1737, for the improvement 

 of the waterworks at the Pont Notre Dame, Paris. The situation of the pivot of the 

 valve, is described to be, at one-twel'th part beyond the line of the geometrical diameter 

 of tbe pump-barrel. 



