Manual of basic techniques for a health laboratory - libdoc.who.int

20 Manual of basic techniques for a health laboratory●●●Never plug a new piece of equipment into the electricity supply without firstchecking the plate to see whether the voltage marked is the same as that of thelaboratory supply (110V, 220V, etc.).Never remove a plug from a socket by pulling the cable.Never replace fuse wire with wire that is thicker.2.3 Plumbing: simple proceduresA fault in the plumbing of the laboratory (a dripping tap, a blocked sink, etc.) canhamper laboratory work considerably. Some simple remedies are described below,in case a plumber is not readily available.Fig. 2.15 Tools and materials for plumbing repairs2.3.1 Tools and materials (Fig. 2.15)●●●●●Adjustable wrenchPipe wrenchSet of screwdriversBottle brushRubber washers for taps● Rubber stoppers such as those used in penicillinbottles● Plunger for clearing blocked pipes● Tow and jointing compound for sealing joints, ifavailable.Important: Before starting any plumbing operation, cut offthe water at the mains.2.3.2 TapsA tap is made up of two parts (Fig. 2.16):— the body (B), through which the water flows— the head (H), which controls the flow of water by means of a rubberwasher (W).Between the head and the body, there is a joint (J) of rubber or tow.Fig. 2.16 Components of a tapB: body; H: head; J: joint; W: washer.Fig. 2.17 Removing the head of a tap