The waste and vent pipes of the ordinary kitchen sink are generally 1 1/2 in. in size. The waste and vent of the kitchen sink, when used in hotel, restaurant, boarding house, and club kitchens, or when used in other public or private establishments which call for its almost constant use, should never be less than 2 in. in size. The amount of greasy matter entering such sinks is very great, even when the utmost precaution is used, and it is very necessary to so construct the work in connection with such a sink that stoppage shall have the least possible opportunity. It is a well-known fact that when sewage containing grease comes in contact with a cold surface, the grease will separate from the sewage and adhere to such surface. This often occurs in soil and waste pipes, the pipes running through cellars being cold and therefore well calculated to collect grease. When the grease begins to collect it continues to increase in thickness, until in time the entire bore of the pipe is filled. The collection of grease practically forms a body of hard soap in the pipe, and a stoppage of such nature cannot be dislodged by ordinary means of forcing stoppages, but necessitates taking down the pipe and clearing out each length.
Plate VII. The Hotel Or Restaurant Sink -The Use Of Grease Traps
Hotel or Restaurant Sink
For this reason, on horizontal lines of waste from sinks used in hotels, restaurants, etc., a cleanout should be inserted at intervals of ten feet in the piping.
Money put into cleanouts on such work as this is always well invested, as their use will eventually avoid the necessity of taking down the waste piping, an expensive undertaking.