| 摘要 |
An automatic regulating valve apparatus, in which a main valve unit is driven interlockingly with a pilot valve unit. The main valve unit is provided in a main valve casing with a main valve disc and a main valve driving member the pressure receiving surface area of which is larger than that of the main valve disc which are incorporated therein in one body. The main valve disc is positioned on the upstream side of the main valve seat and forms a throttled flow passage between the main valve disc and main valve seat. The main valve driving member is fitted slidably in a cylindrical wall portion of the main valve casing and forms a main valve driving pressure chamber between the main valve driving member and the mentioned wall portion. The pilot valve unit comprises a pilot valve A and a pilot valve B which are operated interlockingly with each other, the pilot valve A and pilot valve B which are opened and closed in accordance with the change of the difference between the pressures before and after an orifice provided in the main valve, the liquid level on the downstream side of the main valve unit, and the pressure on the upstream side of the main valve unit communicate in series by a communication passage between the upstream and downstream sides of the main valve unit via the main valve driving pressure chamber formed between these valves. Owing to the interlocking operation of the pilot valve A and pilot valve B, the inner pressure of the main valve driving pressure chamber is changed, and a passing fluid is automatically controlled while controlling the degree of opening of the main valve disc, whereby the automatic regulating functions including the constant flow rate control function, emergency interruption function, liquid level control function and upstream side pressure control function are produced. |
