Disc holder

A rupture disc holder is the structure that encloses and clamps the rupture disc in position. 

This disc holder is rotated at the end T of the stirrer shaft in place of the wire I basket in (ii) above. 

The disc holder was machined to fit into the stainless steel flange in such a way that it directs the gas to consecutively sweep both faces of the catalyst disc, with an expansion volume in-between. This configuration provided good gas-phase mixing in the cell, thus allowing the reactor to be characterized as a CSTR. This mode of internal mixing eliminates the need for internal moving parts or external recycle loops and pumps. 

In addition, analysts can create a multimodal SPE column by stacking several discs with differing bonded phase in the disc holder. With the proper chemical design, such multimodal systems can provide customized separation protocols. The stacking order of the discs depends on the particular physicochemical characteristics of the analysis under way. The general rule is to place the disc with the more selective extraction mechanism on top of the less selective adsorbent. 

Finally release the press and remove the die body (A) and the upper steel pellet from the face of the disc and then remove the disc itself with tweezers (the disc should never be handled with the fingers), and mount it in the specially designed holder. These latter operations are best conducted under a radiant heater. The disc holder is located in position in the sample beam path of the spectrophotometer if required a blank potassium bromide disc, similarly prepared, is introduced into the reference beam path. 

Rupture disc device A device that contains a disc which ruptures when the static differential pressure between the upstream and downstream side of the disc reaches a predetermined value. A rupture disc device includes a rupture disc and may include a rupture disc holder with eventual accessories (e.g. pressure gauge) (Figure 3.1). 

Bursting disc or rupture disc in disc holder... 

The variety of materials available on the market today is immense, and the better manufacturers have designs from carbon steel over stainless steel, to duplex, super duplex, up to Hastelloy and even titanium. Usually body, bonnets and disc holders are made from castings, while a lot of the internal parts are made from bar, but almost any combination is possible today. 

To achieve, however, the adjustable reseat pressure required by the codes, a nozzle ring is added in the design, as shown in Figure 5.3. The nozzle ring, the nozzle and disc holder form the so-called huddling chamber, the strength of which determines not only the opening action but also the reseat pressure. 

Disc holder Has a dual function First, it holds the disc, and second, its skirt or hood shape determines the opening characteristics of the valve as it forms the huddling chamber. It also determines the flow path and hence can have an influence on the flow coefficient. The design of disc holders is very different from manufacturer to manufacturer. 

The stem and spring force is transmitted onto the disc holder via a guide which has vent holes in the bonnet. These vent holes are blocked when a bellows is installed as the bonnet needs to be at atmospheric pressure (vented bonnet) (Figure 5.12). 

The way the stem is connected to the disc holder is different in each SRV design, depending on the manufacturer. It is of course very important that the force be transmitted equally therefore, a lot of designs have a swivelling joint connection so that the disc is correctly aligned on the nozzle. 

The way the disc is fitted in the disc holder also depends on the manufacturer s design. Since the disc is a critical part of the valve, it is important that it can be easily removed for rework, lapping or replacement during maintenance. For instance, the disc holder can be provided with a hole so the disc can be easily snapped out. Otherwise it could become difficult to remove the disc (Figure 5.13). 

The bellows are fitted to cover the top side of the disc holder, in the same area as the nozzle. The way the bellows are fixed depends also on manufacturer design (Figure 5.15). 

It is important that a perfect alignment between nozzle and disc is guaranteed. This can be obtained by a swivelling design of either the stem on the disc holder or by the disc design itself. 

Also, for new installations each installed rupture disc must be purchased along with a disc holder. This holder basically consists of two flanges between which the rupture disc is held. Disc holders are typical for specific manufacturers and are not interchangeable. The same holder may only be used for replacement purchases as long as you buy the exact same rupture disc from the same manufacturer. So the disc type and holder are pretty much a set. 

Galling of guide ID (internal diameter) or disc holder stem 1. Replace the internals and lap the disc. 

This is usually caused by violent cycling of the SRV many times a second. In many instances, this causes the bellows flange to be sheared from the bellows capsule. This way the bellows can even become detached from the disc holder. 

The next is also a bellows failure due to fatigue Indications of galling on the disc holder OD and/or guide ID are evidence that the valve has cycled frequently or has been chattering (Figure 10.13). 

Remove the disc from the disc holder (Figure 10.29). Depending on the design, this can be cumbersome. Some designs have holes in the top of the disc holder where you can push the disc out others you need to use a screwdriver to click the disc out. Others have a lockscrew fitted in the middle of the disc which can be loosened to remove the disc. In any case, make... 

Disc inserts should be lapped in the same way as the nozzles. The disc insert must always be removed from the disc holder before lapping. 

The internal components such as the guide, disc holder, disc insert, nozzle, guide ring and spindle should be cleaned by immersion in a commercial high-alkaline detergent. 

The bearing surfaces on the guide and disc holder should be checked for residual product build-up and any evidence of scoring. 

Mount the filter containing the CSjPtClg on the ring and disc holder as shown in Fig. 5.44. Count the sample using a low background beta detector or by gamma spectrometry. 

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