| 摘要 |
<p>PURPOSE:To remarkably facilitate cleaning of a residual liquid or gas by uniting three valves into one body in one block to remarkably reduce the length of piping and remarkably reducing a liquid sump portion. CONSTITUTION:Three valves 1 - 3 adopting a bellows valve are united into one body in one block, the vale 1 is formed very close to piping A and the valve 3 is formed very close to piping B. Cleaning operation is conducted by closing the valves 1, 3, opening the valve 2, vacuum-sucking one opening of A and B and letting inert gas flow through the other opening thereof. By this operation, a space between the valve 1 or the valve 3 and a cleaning piping is made very small, so that a liquid sump is hard to produce in that portion. Even if a liquid sump is produced, the quantity is very small, so that residual liquid can be easily blown off by vacuum suction and blowing of inert gas. Thus, particles due to hydrolysis of residual liquid are not produced to remarkably decrease the particle density.</p> |
