The Castair Full Flow Ball Valve BV125 is a 1-1/4" NPT ball valve designed specifically for 25-40 HP rotary screw compressors. At $57.60, it is the correctly sized full-flow shutoff valve for the larger discharge lines and higher flow rates of compressors in the 25-40 HP class — where a 1" valve would be undersized and create a bottleneck in the compressed air supply.
Why 1-1/4" for 25-40 HP Rotary Compressors
Rotary screw compressors in the 25-40 HP range produce significantly more CFM than a 5-10 HP reciprocating machine. At those flow rates, the discharge line and all downstream components need to be sized to handle that volume without creating pressure drop. A 1-1/4" full-flow valve at this discharge point keeps the line fully open with minimal restriction, maintaining the pressure the compressor produces all the way to the distribution system.
Using a 1" valve (BV100) on a 40 HP rotary would create a restriction. The BV125 is the correct specification for this compressor class.
Technical Specifications
- SKU: BV125
- Connection Size: 1-1/4" NPT
- Valve Type: Full Flow Ball Valve
- Application: 25-40 HP Rotary Screw Compressors
- Price: $57.60
- Manufacturer: Cast Air (Castair)
Key Features
- Sized for 25-40 HP Rotary Compressors: 1-1/4" ID matches the discharge line specifications of rotary screw compressors in this HP range
- Full Flow Design: Full-port ball bore matches pipe ID — no flow restriction when valve is fully open
- Positive Shutoff: Clean open/close function — holds pressure reliably when closed, no flow when you need the system isolated
- Standard NPT Threads: 1-1/4" NPT connects to standard compressor discharge plumbing without adapters
Applications
- Discharge shutoff valve on 25-40 HP rotary screw compressors
- Distribution system isolation valves on high-capacity compressed air systems
- Shutoff before aftercoolers, dryers, or filters on larger compressor installations
- Any 1-1/4" NPT compressed air application requiring a full-flow positive shutoff
BV Series Selection — Matching Valve to Compressor
BV25 (1/4"): small line, drain valves, pilot connections. BV100 (1"): mid-range reciprocating compressors and 1" lines. BV125 (1-1/4"): 25-40 HP rotary screws. BV150 (1-1/2"): larger compressors and high-flow distribution. Match the valve to your line size and compressor output — call 866-217-0063 if you need sizing help.
Why Buy From OEM Diagnostic Tools?
We have been supplying compressor parts and accessories to shops and industrial buyers since 2016. We stock Castair ball valves in the full size range and can confirm the right specification for your compressor before you order. Free shipping on qualifying orders, full manufacturer warranty, and direct support at 866-217-0063.
Call 866-217-0063 for quick answers and help!
