P133 Gas Pressure Regulator (External Registration)

We stock the P133 in outlet pressures up to 10 PSIG. For outlets over 10 PSIG, or for worker monitor setups, please Contact Us to confirm availability and configure the right unit for your application. The BelGAS P133 gas pressure regulator is a manual, direct-acting, spring-loaded adjustable regulator used in commercial and industrial applications where accuracy and sensitivity are critical — furnaces, burners, boilers, gas engines, and compressors. It uses a balanced diaphragm design to minimize the effects of upstream (supply) pressure changes on the downstream (output) pressure, so it holds a steady, accurate set point even as supply conditions shift. A bubble-tight shut-off means no seat-to-seat adjustment is required, and the regulator reliably operates across a temperature range of -40°F to 200°F. The P133 is particularly well suited to worker monitor setups. Because it's rated for pressure monitoring service, it's a natural fit as the working monitor regulator in a monitor/worker system — providing a second, independent stage of pressure control downstream of (or alongside) a primary regulator for added protection against overpressure events. This makes the P133 a go-to choice anywhere code or good practice calls for redundant regulation. Since worker monitor configurations vary by application, contact us and we'll help you spec the right setup. The P133 uses external pressure registration — an external control line connects the outlet piping to the diaphragm chamber. This is the traditional, field-proven setup and gives installers flexibility in how and where they tap the sense line. Note: If you're looking for a simpler, single-connection install without running an external sense line, we recommend the BelGAS P134 — a variation of the P133 platform with internal pressure registration built in. [Link to P134 product page] The P133 is one of our most popular regulators — it's a direct functional replacement for the Honeywell/American Meter 3000 Series and for Fisher 133 / 133HP / 166 regulators. Features: Suitable for monitoring service Balanced supply valve minimizes effects of supply pressure changes Wide pressure range offering (17 spring ranges across L, H, and K versions) Bubble-tight shut-off — no seat-to-seat adjustment required Available in Ductile Cast Iron or WCB Steel body; Nitrile or Fluorocarbon trim NPT or Flanged (125 FF / 150 RF) connections Rebuild kits available Applications: Industrial and commercial gas regulation Worker/monitor regulator setups (contact us to configure) Natural gas and propane gas regulation Furnaces, boilers, and burners Gas engines Compressors Product Documentation: P133 Spec Sheet P133 Installation & Operation Manual (IOM) P133 Tech Note (Relief Valve Diagram) Specifications Spec Detail Model / Series P133 Type Direct-acting, spring-loaded, non-relieving (external registration) Diaphragm 14" Port Size 2" NPT Connection NPT or Flanged (125 FF / 150 RF) Max Inlet Pressure 150 PSIG (varies by version) Max Outlet Pressure Set + 40 PSIG (varies by version) Max Outlet Flow 170,000 SCFH Cv 51.40 Spring Ranges 2" W.C. up to 60 PSIG (17 ranges across L, H, K versions) — in stock up to 10 PSIG outlet; over 10 PSIG outlet available by request, contact us Body Material Ductile Cast Iron or WCB Steel Bonnet Aluminum or Cast Iron Diaphragm / Trim Nitrile or Fluorocarbon Orifice Material Aluminum Temperature Range -40°F to 200°F Bonnet Orientation 12, 3, 6 (standard), or 9 o'clock Port Orientation Up (standard), Down, Right, Left Application Commercial, Industrial Pilot Operated No Cross-Reference Part Numbers (for search + compatibility) Replaces / Comparable to: Brand Model / Series Honeywell / American Meter 3000 Series Fisher 133 Fisher 133HP Fisher 166 (obsolete) Itron RB1700 Itron RB4000 Sensus 121-12 Sensus 121-8HP BelGAS (sister model) P134 (internal registration version — simpler single-connection install) Suggested cross-reference blurb for the listing: Cross Reference: The P133 is a direct replacement for the Honeywell/American Meter 3000 Series and Fisher 133, 133HP, and 166 (obsolete) regulators, as well as Itron RB1700/RB4000 and Sensus 121-12/121-8HP. If you're replacing any of these models, the P133 is a drop-in upgrade — and if you'd prefer to skip running an external sense line, see our BelGAS P134, which uses the same platform with internal registration for an easier single-connection install.