PIETRO FIORENTINIaperflux 851 3 inch_seal kits
Genuine Pietro Fiorentini Aperflux 851 3-inch seal kit for maintenance and repair.
Product Details
Pietro Fiorentini Aperflux 851 3-Inch Seal Kit — Product Specifications
The Aperflux 851 seal kit is a genuine Pietro Fiorentini replacement parts package designed for maintenance and overhaul of the 3-inch (DN80) Aperflux 851 pilot-operated gas pressure regulator. Using authentic Fiorentini seal kits ensures optimal performance, proper sealing, and compliance with manufacturer specifications.
Seal Kit Contents (3-Inch / DN80):
Component Description
Head Gasket High-temperature resistant gasket for regulator body/bonnet connection
Body Gasket Main body seal for leak-free operation
Balanced Plug Seat Balanced valve seat seal for accurate pressure control
Diaphragm Pack Complete diaphragm assembly including backup rings
Shaft/Bush Seals Stem seals to prevent gas leakage through the operator shaft
Pilot Circuit O-Rings All O-rings for pilot tubing and connections
Auxiliary Seals Additional seals for monitoring and relief connections
Recommended Replacement Intervals:
After reaching specified operating hours (as per technical manual)
Following lockup pressure or creep test results exceeding tolerance
During routine preventive maintenance schedules
After any overpressure incident or abnormal operation
Related: Aperflux 851 Main Regulator Specifications
Parameter Specification
Model Aperflux 851
Type Pilot-operated, fail-open (per EN 334)
Size DN25, DN50, DN80, DN100, DN150, DN200, DN250 (3" = DN80)
Connection Class 150/300/600 RF or RTJ (ASME B16.5); PN16/25/40 (ISO 7005)
Design Pressure Max 102 bar
Inlet Pressure Range 1.3 – 85 bar
Outlet Pressure Range 0.8 – 74 bar (depending on pilot selection)
Minimum ΔP 0.5 bar (recommended > 2 bar)
Accuracy Class (AC) Up to 2.5
Shutoff Class (SG) Up to 10
Temperature Range -20°C to +60°C
Compatible Gases Natural gas, methane, air, dry CO₂, N₂, H₂-blended gas
Available Options Integrated silencer, slam-shut valve (SB/851), monitor regulator (PM/851)
