Sliding ring valve

Use is made of screw tip valves, popularly called non-return valve, ball check valve, or sliding ring valve. They are used in reciprocating injection and injection blow molding machines (IMM and IBMM) to control the melt flow in one direction (Chapter 4). There is also the smearhead for IMM, IBMM, and extruder. Back flow will not occur... 

The poor corrosion resistance of borides may be partially overcome in composites with SiC if the microstructure allows passive oxidation kinetics. In combination with SiC the borides retain their high electrical and thermal conductivity and thus suitable thermal shock resistance. SiC-TiB2 composites have been extensively developed for wear parts in machinery such as sliding rings, valves, valve seats, roller and ball bearings, plungers, and rocker arm pads. 

Front discharge ball check less expensive than sliding ring valve. 

When the melt is forced into the mold, the plunger action could cause the melt to flow back into the screw flights. Generally, with heat-sensitive resins such as PVC and thermosets, a plain or smearhead screw tip is used. For other resins this is not adequate, and a number of different check valves are used. These devices work in the same manner as a check valve in a hydraulic system, allowing fluid to pass only in one direction. These check valves, which are basically a sliding ring or ball check design (Fig. 2-10) are supplied by many manufacturers. Here are some comparisons (100) ... 

Figure 5.60 Nonreturn valves (a) sliding ring/ (b) ball check valve/ and (c) smear tip. ...

Injection Machine Check Valve A free-flowing sliding ring check valve is recommended for use with SPS. A sliding ring check has less restriction and will have a lower pressure drop than other check valve designs. 

It is recommended that the screw design be as follows. The screw is not usually fitted with a standard back-flow valve (of the sliding ring type) due to the risk of stagnation and... 

Bowl does not open Check 1. That tank contains water 2. That cock in conduit from tank is open 3. Control valve 310-1 4. Paring disc device 310-2 5. Control means of bowl Rubber ring C20 for operating 300-4 slide... 

With the flame on, adjust the air vents by rotating the barrel (or sliding the ring). What happens to the flame as the air vents open Adjust the gas control valve and the air vents until you obtain a flame about 3 or 4 in. high, with an inner cone of blue (Fig. 

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