Expanded range multiple-stage metering valve

An expanded-range multiple-stage pintle valve, comprising:

• a) a valve body enclosing a first chamber and having a first axial bore connecting said first chamber to a second chamber;
• b) a secondary valve seat disposed within said first axial bore;
• c) a secondary valve head having a secondary mating surface opposable to said secondary valve seat to regulate secondary fluid flow therebetween, said secondary head having an internal chamber therein, said chamber being in communication with said first and second chambers in said valve body, said secondary valve head further including a primary valve seat disposed between said internal chamber and said first chamber in said valve body, said secondary valve head further including a shaft stop washer disposed coaxially therein;
• d) a primary valve head disposed within said secondary valve head and having a primary mating surface opposable to said primary valve seat on said secondary valve head to regulate primary fluid flow therebetween through said secondary valve head;
• e) a valve pintle for actuating said primary and secondary valve heads, said pintle being connected at a first end to said primary valve head and extending through said secondary valve head and said valve body for actuation by actuating means;
• and
• f) means for engaging and releasing said secondary valve head from said pintle over a portion of the stroke of said pintle actuation.

An expanded-range pintle valve, comprising:

• a) a valve body having a chamber therein and inlet and outlet means including a secondary flow seat;
• b) secondary valve means disposed within said chamber for regulating flow across said secondary flow seat and including a primary flow seat;
• c) primary valve means disposed within said secondary valve means for regulating flow across said primary flow seat through said secondary valve means;
• d) pintle means extending through said secondary valve means and attached to a primary valve head in said primary valve means for actuating said primary valve means;
• and
• e) means for selectively causing said pintle means to actuate said secondary valve means.

An expanded-range pintle valve, comprising:

• a) a valve body having a chamber therein and inlet and outlet means including a tertiary flow seat;
• b) tertiary valve means disposed within said chamber for regulating flow across said tertiary flow seat and including a secondary flow seat;
• c) secondary valve means disposed within said tertiary valve means for regulating flow across said secondary flow seat through said tertiary valve means and including a primary flow seat;
• d) primary valve means disposed within said secondary valve means for regulating flow across said primary flow seat through said secondary and tertiary valve means;
• e) pintle means extending through said tertiary and secondary valve means and attached to a primary valve head in said primary valve means for actuating said primary valve means;
• and
• f) means for selectively causing said pintle means to actuate said secondary and tertiary valve means.