Description des marchandises
THE PRODUCTS CLASSES AS CARBON GRAPHITE MECHANICAL SEAL PARTS. A MECHANICAL SEAL HAS 2 FACES, ONE THAT IS CALLED THE STATIONARY OR SEAT FACE, AND IS FITTED INTO A PUMP CASING OR HOUSING, THE OTHER IS CALLED THE ROTARY FACE, AND IS SEALED ONTO THE PUMP'S ROTATING SHAFT, TYPICALLY WITH A RUBBER SEALING PART, LIKE A MOULDED BELLOWS OR AN O-RING, AND SOME METAL PARTS TO HOLD THE ROTARY AND RUBBER PARTS TOGETHER, AND A METAL SPRING TO PRESS THE ROTARY AGAINST THE SEAT WHEN THE SEAL IS INSTALLED. MECHANICAL SEAL FACES GO THROUGH A PROCESS CALLED 'LAPPING' TO MAKE THEM EXTREMELY FLAT ON THEIR CONTACT SURFACES, AND TO PUT IT SIMPLY THEY WORK BY THE PROCESS OF THESE VERY FLAT FACES BEING PUSHED TOGETHER; THE FLATNESS MEANS THAT THERE ARE NO GAPS WHERE FLUID CAN GET THOUGH WHEN THE FACES ARE TOGETHER. THE ROTARY FACE IS PUSHED UP AGAINST THE STATIONARY FACE, AND EVEN THOUGH THE ROTARY IS TURNING, AND THE ROTARY FACE REVOLVES AGAINST THE STATIONARY FACE, THE ROTATING SHAFT IS MADE FLUID-TIGHT. THESE CARBON PRODUCTS ARE MECHANICAL SEAL FACES - THEY ARE NOT THE COMPLETE SEAL, THEY ARE A PART OF ONE. THEY ARE NOT BEARINGS, ALTHOUGH IMPREGNATED CARBON BEARINGS DO EXIST, AGAIN BECAUSE OF THE BENEFICIAL SELF-LUBRICATION PROPERTIES OF THE MATERIAL. BUT WHILE A CARBON FACE AND A CARBON BEARING MIGHT LOOK SIMILAR TO THE UNTRAINED EYE, THEY ARE NOT THE SAME, AND THEY DO NOT SERVE THE SAME PURPOSE. BUT BOTH MECHANICAL SEALS (OFTEN WITH CARBON FACES IN THEM) AND BEARINGS ARE BOTH NECESSARY ITEMS ON A ROTARY PUMP.
