Inflatable Seated Butterfly Valves
Series 485, 486, 487, 488
ANSI and Metric Flange Compatible
Less friction, low torque, less wear, longer life.
Posi-flate’s unique butterfly valve design uses air pressure to expand the seat against the disc, providing even pressure distribution for a bubble-tight seal, every time. Because the seat makes only casual contact with the disc during valve opening and closing, there is very minimal disc impingement. This is in contrast to conventional butterfly valves where disc impingement leads to shaving of the seat, decreasing the overall performance and valve life.
Substantially less torque is required to open and close the Posi-flate butterfly valve, thus a smaller actuator can be used resulting in lower overall valve cost.
In actual comparison tests and documented field applications, the Posi-flate butterfly valve outperformed all other valves. In fact, a Posi-flate valve life of one to three million cycles, even in extremely abrasive applications, is not uncommon. For dry solids, gases and slurry applications, the Posi-flate inflatable seated butterfly valve is unsurpassed.
Standard valve sizes range from 2″ (50 mm) to 30”” (800 mm) and fit both ANSI and metric flanges. A full line of actuators, limit switches and controls are available to suit individual applications.
Performance Features
- Inflatable seat compensates for disc and seat wear
- Longer valve life
- Minimal seat wear
- No disc impingement
- Ultra-low torque requirements
- Lower actuator costs
- More seal contact area
- Proven excellent for abrasive and dry solids
- Disc designed to prevent material build-up
- Double shaft seals
- Multiple bearings
- Fail-safe monitoring
Temperature limits: -40° to 350° F (-40° to 175° C), varies with application and materials of construction.
Air supply: 115 PSIG (7.9 bar) maximum to seat, varies with application.
Working pressure: Full vacuum to 100 PSIG (6.9 bar), varies with materials of construction.
Operating torque: Varies with application.
Available Materials of Construction
Housing: Cast iron, stainless steel, aluminum, nickel-plated cast iron, epoxy coated cast iron, nylon coated cast iron
Resilient Seat: EPDM, Buna-N, polyurethane, fluoroelastomer, FDA silicone, FDA white Buna-N, FDA white EPDM, FDA white fluoroelastomer
Disc: Cast iron, 316 stainless steel (satin or polished), molded nylon. PFAS-free non-stick, nickel and nylon coating available
Disc Screws: Carbon steel, stainless steel
Bearings: Nylon, bronze
Shaft: Zinc-plated carbon steel, 316 stainless steel
Shaft Seal: Buna-N, fluoroelastomer
Housing Gasket: Buna-N (Series 486, 487, 488)
Retaining Ring: Carbon steel, stainless steel
Housing Bolts: Carbon steel, stainless steel
Series
Series 485
Single piece housing with disc and shaft. Sizes 5” (125 mm) to 30” (800 mm).
Series 486
Split housing with integral stainless steel disc and shaft or integral molded nylon disc and stainless steel shaft. Sizes 2” (50 mm) to 30” (800 mm).
Series 487
Split housing with disc and shaft. Size 4” (100 mm).
Series 488
Split housing with integral cast iron disc and shaft. Sizes 2” (50 mm) and 3” (80 mm).
Design features for reliable performance
A. ACTUATOR MOUNTING FLANGE: Flange is designed for direct actuator mounting.
B. RETAINING RING: Retaining ring simplifies bearing and seal removal and ensures positive bearing retention.
C. BEARINGS: Multiple bearings substantially reduce operating friction and torque requirements eliminating any metal-to-metal contact, thus preventing shaft galling and freezing.
D. SHAFT SEALS: O-ring shaft seals insure positive sealing under the most adverse conditions.
E. SHAFT: Corrosion resistant, high strength steel shaft is easily replaceable.
F. SEAT O-RING SEAL: O-ring provides long lasting positive seal of seat inflation pressure.
G. MATERIAL SEAL: Land seal prevents material contamination of seat o-ring seal.
H. DISC/SHAFT: Integral disc and shaft with smooth, contoured surface provides minimum resistance to flow and reduces material buildup.
I. AIR INLET PORT: Oversized inlet port allows quick valve pressurization/
depressurization.
J. DISC: Smooth contoured surface assures extended seat life and disc is easily replaceable.
K. DISC SCREWS: Self-locking screws of high tensile steel provide strong link between disc and shaft, yet allow easy disassembly.
L. HOUSING: Rugged one-piece body fits standard 125/150 class ANSI flat-faced flanges and PN 10 metric flanges.
M. HOUSING GASKET: Die cut elastomeric gasket assures leakproof housing.
N. HOUSING BOLTS: High strength steel bolts maintain structural integrity of housing under the most adverse conditions.
O. SPLIT HOUSING: Rugged two-piece body fits standard 125/150 class ANSI flat-faced flanges and PN 10 metric flanges. Minimizes assembly time and allows for integral shaft and disc.
P. RESILIENT SEAT: Easily replaceable, the inflatable molded seat has a smooth contour locking design to minimize stress and hold the seat in place, eliminating any need for flange gaskets.