Demco Butterfly Valve

• Driving Mode: Manual
• Structure: Centre Sealing
• Seal Form: Force Sealed
• Valve Stem: Orbit
• Work Pressure: Low Pressure (Pn<1.6MPa)
• Working Temperature: Normal Temperature (-40°C<T<120°C)
• Model NO.: YDMB-1
• Material of Seal Surface: Soft Sealed
• Valve Body: Sheet Metal
• Application: Industrial Usage
• Connection Form: Lug or Wafer
• Transport Package: Export Package
• Specification: 2"-12"
• Trademark: YOUYAO
• Origin: China
• HS Code: 8481804090
• Production Capacity: 5000sets/Month

Product Description

DEMCO Resilient Seated Butterfly Valve
Installation, Operation and Maintenance Manual

DEMCO Resilient Seated Butterfly Valve
Installation, Operation and Maintenance Manual
Page 4 of 12
Bill of Materials
ITEM REQ'D DESCRIPTION
1. 1 Body
2. 1 Seat
3. 1 Disc
4. 1 Upper Stem
6. 1 Lower Stem
7. 2 Spring Pin
14. 1 Retainer
22. 1 Top O-Ring
23. * Stem O-Ring
24. 2 Bearing
Figure 1 - Demco 2" thru 12" Resilient Seated Butterfly Valve
Demco
Installation
Direction -
Demco butterfly valves are bi-directional and will
operate in any position. Normally the valve is
installed with the upper stem pointing upward
(Figure 5). Elevated valves with gear operators and
chainwheels should be installed with the upper
stem pointing down (Figure 6) so the open-closed
indicator is visible from the ground and the chain
does not drag on the pipe.
End-of-Line Service -
Demco tapped lug butterfly valves are suitable for
liquid service end-of-line applications with downstream
piping removed (Figure 7). Only weld neck
or socket weld flanges can be used for this service.
Since the upstream pressure is excluded between
the flange and the seat face by the exclusive
Demco flange seal, there is no effective force to
slide the seat downstream.
 

Size	Inch
DN50	2"
DN65	2.5"
DN80	3"
DN100	4"
DN125	5"
DN150	6"
DN200	8"
DN250	10"
DN300	12"