Pump control valves; valves as machine components; thermostatic control valves for machines; valves being parts of machines; valves being parts of machines operated pneumatically and by air; valves for pumps; back pressure valves as parts of machines; engine exhaust systems comprised of particulate traps; hydraulic controls for machines, motors and engines; pneumatic controls for machines, motors and engines; pneumatic air preparation equipment, namely, airline filters, lubricators, and regul...