The disc is in two halves, spring loaded, that seat on parallel seat rings. Kvt parallel slide spring loaded gate valves are supplied with three types of bodybonnet closures. It is named after the hollow central dsectioned piston. Learn more about parallel gate valves on globalspec.
There are four basic types of flow control elements employed in valve design. Parallel slide and wedge type gate valves, designed for. But this works only if the valve is manufactured with high precision, which is why such valves find use in bigger, more costly applications, where reliability of true shutoff is mandated. Kvt hifluidic kvt parallel slide gate valves flduantages of rut parallel slide gate llalue ouer other types of gate llalue exceptional design features of spring pack loadedspl parallel slide gate valves, kvt parallel slide gate valvespsgv are designed for more reliable sealing tightness and valve opera tion in fluid flow control. Gate valve is a linear motion valve that used to start or stop the fluid flow. Rotate a disc or ellipse about a shaft extending across the. The advantages of this product versus the traditional wedge type product are. Unique parallel slide forged cage unit design comprises all operating parts of the slide discs.
We reserve the right to modify or improve the designs or specifications of such products at any time without. Features a range of compact pressure seal gate valves designed according to asme b16. It is a linear motion valve used to start or stop fluid flow. The gate is designed to slide along the edge of the mezzanine to allow access to the mezzanine. The top countries of suppliers are india, china, and india, from which the percentage of parallel. This type of onoff valve is an alternative to the traditional wedge type gate valves.
The disc slides in contact with the seats, hence the name. Increased plant and personnel safety is made possible. Parallel slide valves parasura parallel slide has kosos own designconstruction to realize very good and firm metaltometal touch sealing performance. The parallel gate valve in design pushes the debris off the parallel seals as the valve is shut. Valve suppliers often receive quote requests for a knife gate when what a company is really looking for is a slide gate for dry bulk material handling. You can also choose from brass, stainless steel, and rubber parallel slide valve there are 70 suppliers who sells parallel slide valve on, mainly located in asia. A wide variety of parallel slide valve options are available to you, such as manual. Parallel slide and wedge type gate valves, designed for use in power industry applications. Parallel slide pressure seal bonnet gate valves fluitek. Due to the valve design, incorporating a small facetoface dimension and lower weight than most valve types, the butterfly valve is an economical choice for larger line sizes i. Parallel slide and wedge type gate valves, designed for use. Parallel slide valves in hc service your experiences.
This valve worked by connecting the upper and lower valves so as to be worked by one rod or spindle, and in making the stem or tube which connects them hollow, so as to serve for an induction pipe to the u. Parallel slide gate valve psg the valvtechnologies parallel slide gate valve psg addresses advanced design features and benefits and the need for true inline valve reparability in large diameter, highenergy piping systems resulting from those enhancements. Whats the difference between a knife gate and a slide gate. The term valve stems from the latin valva, which means moving part of a door. Ian sutton, in plant design and operations second edition, 2017. Perhaps your manager had in mind the double expanding gate valve type. Not only does this prolong the lifespan of the valve, but ensures low. The higher pressure in the system, the better closing tightness. Tight shut off achieved by line pressure not from mechanical. Spring loaded discs assures good sealing performance between the discs and seatrings in small pressure differential services. Tight shut off achieved by line pressure not from mechanical wedging action therefore eliminating thermal binding. As the piston descends, the valve moves upwards to.
What is the difference between parallel gate valves and. This picture shows wyle laboratorys blowdown test for a velan 8 class 900 loop isolation valve. Fluid tightness is maintained without a wedging action, but instead using the line pressure design features. Gate valves use linear type of stem motion for opening and closing of a valve. Parallel gate valves are slide valves with a parallelfaced gatelike closure member. However, many cases have shown that it always stops doing the regulation a short period of time after the bootstart of the compressor. Somewhat similar to the parallel slide however the slab is split in two parts, each with a vshape wedge like profile. Stainless steel casting to bs3100316c16 valve stem. Parallel slide gate valve gate globe and check yancheng. Steam enters via the steam port sp, and is admitted by the slide valve sv through the upper passage s to push down the piston p.
All range is offered in four standard cast materials. These valves use parallel or wedge shaped discs as closure members that provide tight sealing. Lv7860 flanged pn16, cast steel astm a216 wcb body, tda 58 copper nickel silicon alloy seat rings, stainless steel stem, exfoliated gland packing, bs970 431 s29, designed to bs en 1984 rated pn16, temperature 0c to 425c. Cookies enable websites to access information about the pages you visit and your actions and preferences such as login, language, font size, and other display preferences over a period of time. Velan is a world leader in the design and production of a wide range of cast and forged steel gate, globe, check, ball, tripleoffset butterfly, knife gate, highly engineered severe service valves, and steam traps offering superior performance across all major industrial applications. The ball or plug valve is probably the oldest form of shutoff device in piping technology. The outstanding feature of the parallel slide type v.
The wedge gate concept has been selected by flowserve for its equiwedge gate valve because of several functional advantages. A doubledisk parallel gate valve has two parallel disks that are forced, on closure, against parallel seats by a spreader. Gland and flange they are in forged steel and are supplied in two pieces, selfaligning design to permit the gland to descend parallel to the stem even if the eyebolts are unevenly. At the same time, exhaust steam from below the piston passes back up the lower passage s, via the valve cavity, to exhaust e. Valvtechnologies metalseated parallel slide gate valves are shown in appendix a, figures 1, 2 and 3 fig. Cast steel parallel slide valves the peter smith valve. A knife gate valve is a component that utilizes a blade to cut through clogging of heavy.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. This failure might be attributed to the thermal and gas force deformation of the slide valve or the cylinder. In piping technology, a valve is a piping component which controls, directs or mixes the fluid flow by opening, closing, diverting or partially obstructing the passage through itself. Due to the valve design, incorporating a small facetoface dimension and lower weight than. Slide gate valve single disc or knife gate valve ball and plug valves. It is designed to permit removal from the bonnet or the yoke whilst the valve is in service. A parallel slide gate valve is much less likely to get stuck in the closed position. The d slide valve, or more specifically long d slide valve, is a form of slide valve, invented by william murdoch and patented in 1799. Parallel slide valves, south wales cambrian valves.
There is international acceptance that where arduous duties with high pressure hot water and steam are concerned the parallel slide isolating gate valve is superior to all forms of wedge gate valves, and to globe stop valves. Internationally recognized valve type for high pressure steam and high pressure water isolation. A fully open ball valve behaves as an extension to the pipe and thus does not disturb the velocity profile in the way that, for instance, butterfly and globe valves do. A parallel slide gate valve generally provides better shut off than a wedge gate. Parallel slide bolted bonnet gate valves fluitek orsenigo. Stem guide on a parallel slide valve, an external stem guide serves two important functions. Stainless steel casting to bs1504425c11 valve seat.
The potential for failure to open of wedge gate and parallel slide valves, under certain process conditions may be. Engineering fundamentals for selecting the right valve design for every industrial flow application, fifth edition. Used in high pressure and high temperature applications, the unique design of the taylor parallel slide isolating gate valve allows it to maintain fluid tightness without the aid of any wedging action thereby eliminating mechanical stresses between the discs when opening or closing the valve. Sempell dewrance parallel slide gate valves high pressure. Velan pressure seal parallel slide gate valves are ideal for clean service and steam. A cookie is a small text file that is placed on your computers hard drive by your web browser when you visit a website. For steam generators that frequently start up and shutdown this is a major issue. Pressure seal parallel slide gate valves datasheet. The valvtechnologies parallel slide gate valve psg addresses the need for true inline valve reparability in large diameter, highenergy piping systems.
A gate that can be opened or closed by sliding in supporting guides. Blackhall taylor valves high pressure steam valves. The peter smith valve company is an independent company, established in 1969, specialising in valves for the control of fluids in water systems. Parallel slide gate valve provides a smooth flow path between seats. Cast steel parallel slide valve flanged pn16 leengate.
This is because the gate is not torqued into the seats like a wedge gate. Hifluidic high energy service valves key valve technologies. Cast steel psgv standard design data cast steel parallel slide gate valves hifluidic psgv series class valve size inch 2. Parallel slide gate valves can be supplied with vported outlet seat making them ideally suitable for regulating duties. Body made of superior strength forgings and optional cast steel. Split wedge disk consists of two solid pieces and holds together with the help of special mechanism. Fluitek orsenigo valves has very extended experience in manufacturing this type of valve. In accordance with bsi, bs en 1984 and ansi specifications. Kvt om manual, hifluidic parallel slide gate valve key valve. As often as the two terms are intermingled, a knife gate and a slide gate are not the same. It can be opened either manually or electrical power. In 1996, key valve technologies became a member of the high energy alliance of manufacturers, consisting of hp valves b. With a substantially lowered failure rate, its rack and pinion construction is flanged to meet ansi, bs, or european standards. The disc is pushed to the seat at the low pressure side to ensure the sealing in the high pressure differential services.
Its execellent shutoff performance, brought about by the metaltometal sealing, makes it suitable to a variety of severe services, including emergency shutoffopening at extremely. Bronze or lead ball and plug valves were used by the ancient romans as early as in the centuries b. The gate relies for seat tightness on the primary fluid pressure acting on the downstream half. Types of gate valve and parts a complete guide for engineer. Parallel slide design the gate is a split design using two discs spring loaded and held together by a gate holder with an spring to provide initial energizing when closed. They are an alternative to the traditional flex wedge type gate valves. The objective of this highenergy flow test is to qualify a velan gate valve for simulated severe accident conditions such as loss of coolant accident loca or a line break in a candu nuclear power station. Slide a flat, cylindrical, or spherical surface across an orifice for example, gate and plug valves. Spring loaded discs assures good sealing performance between the discs and seatrings in small pressure.
Switch valves for coking service 20 valvtechnologies, inc. The split disk can be in a wedge shape or a parallel disk type. A gate valve is the most common type of valve that used in any process plant. The slide valve is used to regulate the capacity of a single screw refrigeration compressor. Gates also are bidirectional and normally have similar flow characteristics in both directions.