Dairy equipment have number of joints and connections requiring leak proof arrangement. Stationary equipment like plate type heat exchanger (chiller or pasteurizer) will have gaskets between individual plates. Moving or revolving equipment such as pump shaft or cream separator will require shaft seals, ‘O’ rings etc.
i. Characteristics of rubber and gaskets
All of these must be chemical resistant, as acid and alkali are used as detergents.These should be resilient to offer leak proof joints. These are of varied shapes and sizes to suit particular location or purpose for which these are used. They are required to work under high temperature and preserves, yet should not got damaged or contaminate the milk and milk products. It is, therefore, important that the rubber and gaskets should be of non-toxic material, should be heat resistant, durable and should not get damaged with the chemicals used for cleaning.
ii. Care with gaskets and seals
These have comparatively shorter life, hence require utmost care. Since these are between joints or moving parts, over tightening be avoided. You will notice leakage from pasteurizer at the start. Slowly the leakage will reduce and may stop without tightening the plates. This is due to heat expansion taking place. If you notice leakage even after enough warming up, then plates may be tightened. Over tightening may permanently deform the gaskets. This will result in reduced thickness/gap between the plates. Ultimately, this will affect the capacity of pasteurizer. Similarly packing/’O’ ring in the union or joint should not be over tightened. Usually a good joint should be leak proof. This could be made leak proof by hand tightening and does not require a spanner. Gaskets between pipe joints get damaged while reassembling. This is due to poor alignment of pipelines. As discussed in the previous chapter, the alignment must be corrected before tightening the joint.
iii. Pump seals
These also need good care. Seals are expensive and require correct assembling.The carbon seal face rubs the stationary wall of the pump body, hence, the surface should be well polished and clean. While fixing the new gasket, old gasket and its particles should be removed with either a gasket remover or cleaned with the help of a sand paper.
i. Characteristics of rubber and gaskets
All of these must be chemical resistant, as acid and alkali are used as detergents.These should be resilient to offer leak proof joints. These are of varied shapes and sizes to suit particular location or purpose for which these are used. They are required to work under high temperature and preserves, yet should not got damaged or contaminate the milk and milk products. It is, therefore, important that the rubber and gaskets should be of non-toxic material, should be heat resistant, durable and should not get damaged with the chemicals used for cleaning.
ii. Care with gaskets and seals
These have comparatively shorter life, hence require utmost care. Since these are between joints or moving parts, over tightening be avoided. You will notice leakage from pasteurizer at the start. Slowly the leakage will reduce and may stop without tightening the plates. This is due to heat expansion taking place. If you notice leakage even after enough warming up, then plates may be tightened. Over tightening may permanently deform the gaskets. This will result in reduced thickness/gap between the plates. Ultimately, this will affect the capacity of pasteurizer. Similarly packing/’O’ ring in the union or joint should not be over tightened. Usually a good joint should be leak proof. This could be made leak proof by hand tightening and does not require a spanner. Gaskets between pipe joints get damaged while reassembling. This is due to poor alignment of pipelines. As discussed in the previous chapter, the alignment must be corrected before tightening the joint.
iii. Pump seals
These also need good care. Seals are expensive and require correct assembling.The carbon seal face rubs the stationary wall of the pump body, hence, the surface should be well polished and clean. While fixing the new gasket, old gasket and its particles should be removed with either a gasket remover or cleaned with the help of a sand paper.
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