Valves to isolate machinery, equipment, and piping components for system operation, maintenance and overhaul, and damage control. There are four basic types of stop valves: gate, globe, ball, and butterfly.
- Ball valve – Ball valves have a relatively short actuating mechanism and the body length, and provide a more compact installation than globe or gate valves.
- Butterfly valve – Butterfly valves are the most compact of the stop valves; they have relatively low pressure loss.
- Gate valve – The gate valve is closed by interposing a flat or tapered element (gate or wedge) transversally across the axis of the opening.
- Globe valve – The globe valve is closed by pressing a disc axially against the opening. When the disc is not attached to the spindle, the globe valve is considered to be screwdown non-return valve (SDNR).