Valves for Polymer Industry
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SchuF Polymer Valves SchuF’s polymer valves were originally designed together with the polymer pioneers in the early stages of polymer development. SchuF can proudly claim that it developed more original polymer valves than anybody else. The first diverter, multiport and in-line sampling valves came from SchuF as well as the first bottom drain and lift-plug valves. Additive injection for PET, steam injection, stripper and killer valves for PVC and PP were all developed in SchuF's offices. SchuF's polymer valves are used to drain, feed, changeover, sample, inject, distribute and control Polyester (including PET), Nylon, PVC, PP, PU, HDPE, LDPE and related polymers. Most applications are in Polyester plants. In this brochure, we will look at valves and solutions for the above processes. More detailed leaflets are available for each valve type. SchuF’s strengths are its flexibility of design and construction, it's unrivaled experience with the media and the way all its valves can handle vacuum, high pressures and temperatures as well very high viscosities, while eliminating "dead" and "slow" spaces, avoiding impurities and reducing residence times. SchuF offers cast valves to optimise polymer flow and forged or welded constructions where material integrity is of maximum importance. In all cases the flow path is optimised by the contour of the valve's body and moving parts. SchuF can provide valves with and without replaceable seats depending on start-up conditions. SchuF offers the best high pressure sealing by a judicious combination of different grades of stellite and a specially angled seat to achieve a tangential "zero force" seal. For vacuumtightness, special aluminium grade sealing rings offer leak tightness under 10-6 torr.l.sec-1 and a Helium vacuum test to prove it. We can offer you performance and seat testing under low or high temperatures, und high pressure or vacuum, with Helium, Nitrogen or water ... whatever is required. SchuF is not only the first polymer valve company to have obtained ISO 9001 approval but also the only one with TRD 801 Nr. 45 which allows us to design and build high pressure vessels. In short SchuF offers unmatched experience and individual solutions to specific polymer handling problems. SchuF - the superior polymer valve!

SchuF Polymer Valves Feeding Valves Disc valves are better suited than ram valves for feeding low viscosity feedstocks into reactors. However it may be necessary to adapt the shape and polish the disc and seat. For VC, a bellows seal is recommended to meet the stringent VC pollution requirements. Disc control valves such as the 25BS are used to regulate the level in PVC reactors. 25RC For Polyester, Type 24BH, control valves are used to regulate the flow into the esterification and polymerization reactors. For vacuum service, bellows are generally used. As they are susceptible to failure in...

SchuF Polymer Valves To rinse polymer reactors, especially in the production of PVC a spray rinse valve can be used after a number of batches. Unlike other valves our valve directs the spray pattern specifically at the bottom of the reactor first, before rinsing the sides and then directing the cleaning agent backwards towards the vessel dome. Since the dome and bottom pad are the parts most in need of cleaning this approach has brought very good results using only half the number of valves otherwise required. The valve is used with water or steam at up to 40 bar. Sometimes catalyst or...

SchuF Polymer Valves Dump Valves Dump valves (63WD) are modified lift-plug or diverter valves which are specifically designed to dump polymer during start-up. Once the required quality level has been reached, the valve is switched and offers unimpeded, dead space free in line flow to the filters, chippers and spin blocks. Multiport Diverter Valves Polymer lines are getting bigger, but the chips or spun threads are still the same or becoming finer. Somehow the lines need to be subdivided. Diverter valves eliminate multiple in-line valves with associ42TK ated distributor T-pieces and piping...

SchuF Polymer Valves In direct spinning polymer plants, it is important that the pressure at the spinheads is constant. A chip line is often added to take the overflow. The flow to the chipper line is varied using a flow control valve. Different types are in use, be they take-off or branch valves (39RC) with a traditional control pis- ton tip or a diverter valve in which one of the outlets is controlled by a rotating and specially con- toured piston (42RC) or the unique Type 71VC where the pressure drop is controlled by the varia- Filter switching Valves Switching duplex filters is a tricky...

SchuF Polymer Valves The turning forces involved in turning the piston become very high at high pressures and larger piston diameters. This problem can be overcome by SchuF's unique two stage hydraulic cylinder. 43TC An alternative is the rotating disc valve type 43TC. It combines the advantage of the contoured rotating piston, (indeed the disc and piston tops are exactly the same), but is easy to turn and available with a back seat option. The "forced flow option" features a SchuF patented disc valve, 43TF, with contoured but non-rotating discs. Computer aided FEM simulation optimizes...

SchuF Polymer Valves All switching valves offer the option of integrating vent, flush and drain valves in the inlet and outlet valves to allow for flushing and cleaning of the filters. Further details are available in our brochure "Polymer Filter Switching Valves". Sampling Valves SchuF line drain and sampling valves allow the user to take a sample under high temperature and pressure or vacuum. They can also be used to drain a line in a shut-down situation, to flush or purge it or even as a simple injection valve. The standard valve is welded directly into the centre of the line. It comes...

SchuF Polymer Valves Originally designed by SchuF in the 1960's these valves combine a bot- tom outlet piston or an end of line Y-globe valve with a stranding dye head. They are used in Polyester and Nylon polymerisation plants and offer a short, smooth flow path to the die nozzle. Bellows stem sealing is available to prevent oxygen leaking into the process. A distributor ensures that the round valve outlet is changed to a rectan- gular slit while maintaining equal flow time. The die can be a slit or hole design. The nozzles come with a seal plate which can be manually or automatically...