Description
SMC AR825-12 — AR425-935 series pilot operated regulator with 1-1/2" ports, internal pilot relieving type. Sized for main line duty where a direct acting regulator cannot hold the setting against the flow.
Specification — AR825-12
| Series |
AR425-935 (pilot operated regulator) |
| Body size |
825 |
| Port size |
1-1/2" (code 12) |
| Type |
Internal pilot, relieving |
| Product weight |
2,500 g |
Pilot operated or direct acting
A direct acting regulator balances the outlet pressure against a spring, and the setting sags as flow rises — acceptable on a machine branch, not on a main line where demand swings as plant cycles. A pilot operated regulator uses a small internal pilot to control a large main valve, so it holds its setting across a much wider flow range. On a 1-1/2" line that difference shows up as stable pressure at the far end of the plant instead of a reading that moves every time a large cylinder fires.
Relieving type
If downstream pressure rises above the setting — from thermal expansion, from a cylinder being pushed back, or from someone turning the knob down — a relieving regulator vents the excess to atmosphere instead of trapping it. On a non-relieving unit the only way down is to bleed the line manually.
Typical use
Main line pressure control at the compressor room outlet or building entry, and ahead of large air preparation sets.
Ordering
Order by the full code AR825-12. Port size, gauge and bracket options are all in the code — the G suffix adds a gauge and B a bracket, so AR825-12BG carries both. This size is usually made to order rather than stocked; tell us the quantity and we will confirm lead time with the price.
Supply from Korea
Genuine SMC, sourced through Korean distribution and shipped from Gyeonggi-do with export packing and commercial documents prepared as standard.
