Housekeeper seals

They require a lot of space because of the need for glass-to-metal seals (Housekeeper seals) on each side of the tap and even more if small spirals are included. The purpose of these spirals is to absorb any movement which occurs as the tap is manipulated. This is particularly worthwhile for metal valves which often require more force to turn. 

Fig. 2.16. The PlEgli valve. A stainless steel ball bearing, B orifice to be closed by A, C copper bellows, D cover-plate, E sharp annular ridge, F channel full of solder, G, H sockets for Housekeeper seals, J screws securing D to body of valve.

Fig. 2.17. The Krummenacher valve. A yoke, B spindle, C handle, D metal bellows, E ball-and-socket joint, F annular knife-edge, G annular trough filled with soft metal, H cylindrical heating elements fitting into cavities in the metal body A/, J sockets for Housekeeper seals.

Copper-to-glass seals (Housekeeper seals) and stainless-steel-to-glass seals can be made and the directions may be found elsewhere.8 9 These seals are somewhat strained and are generally not suitable if the joint is exposed to wide temperature variations. 

Housekeeper Seals. Ductile metal seals to glass. For example, a glass bead can be applied to the thinned end of a copper tube, and then sealed to a glass tube, the ductile thinned copper yielding... 

Phylmar s vision is that the Inner Circle might be viewed an indicator of high quality EHS and sustainability consulting work, similar to the Good Housekeeping seal of approval. Firms can trust that Inner Circle members have been prequalified, follow the same set of contracting rules, and are guaranteed to perform work to their client s satisfaction. 

Segregation is practised to allow for housekeeping, construction and maintenance requirements and to reduce the risk of an accident resulting in a domino effect , e.g. from a fire, explosion or toxic release. For very toxic substances, e.g. prussic acid (HCN) or tetraethyl lead, this may involve isolating the entire manufacturing operation in a separate unoccupied building or sealed-off area. 

Tubular seals can be made by several methods reported by Housekeeper, of which three are described here. 

Glass tubing must be sealed on either side of the disc in this manner so that stress is taken up by the disc contracting and not by it bending, which would fracture the seal. Housekeeper reports that a disc up to 2-5 mm thick has been used but the residting seal would not stand heating or cooling. 

Housekeeper, W. G., 1923, J. Amer. Inst, elect. Engrs, 42,954. Partridge, J. H., 1949, Glass-to-Metal Seals-, Sheffield, Society of Glass Technology. 

As described by W. G. Housekeeper (1923), platinum wire of 0-05 mm diameter can be successfully sealed through Pyrex if the wire is first flattened and the edges filed to a sharp V-shape as shown in Figure 42, I. The flattened portion of the wire is fused into a tube whose end has first been collapsed down until it will just take the broad part of the wire. Alternatively the wire may be beaded first,... 

Equipment wash solvent and water, laboratory samples, surplus chemicals, product washes and purifications, seal flushes, scrubber blowdown, cooling water, steam jets and vacuum pumps, leaks, spills, spend or used solvents, housekeeping (pad washdown), waste oils and lubricants from maintenance, and others... 

Improved housekeeping can often lead to reduced emissions and waste.200 The leaky valves and seals can be fixed or they can be replaced with new designs that minimize emissions.201 These include diaphragm valves, double mechanical seals with interstitial barrier liquids, magnetic drives, better valve packings, filled fabric seals for floating roof tanks, and so on. Older plants may have some of the... 

Copper-glass seals are made with Housekeeper technique with thin metal sections. Care must be taken to prevent overoxidation of copper. 

FIGURE 2.53 Housekeeper type of seal, and procedure for making it ... 

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