58
Installation, Operation and Maintenance Manual
MAN 564 Rev. 6
June 2020
Layouts
Section 7: Layouts
Table 26.
Parts list
Item
Qty.
Description
Material
1
2
O-ring
*NBR rubber
2
2
Yoke bushing
Carbon steel
3
2
Washer
Stainless steel
4
1
Housing
Carbon steel
5
1
Guide bar
Alloy steel
6
1
Yoke
Carbon steel
7
1
Cover gasket
*SBR + Cel Fillers
8
1
Guide block
Carbon steel
9
1
Bushing
Steel + Fiberglide
10
2
Sliding block
Carbon steel
11
1
Vent valve
*Stainless steel + Fluorosiliconic rubber
12
12
Screw
Carbon steel
13
1
Cover
Carbon steel
14
1
Guide block pin
Alloy steel
15
-
-
-
16
2
Screw
Stainless steel
17
2
Yoke supporter washer
Ertacetal
18
2
Yoke bushing seat
Steel + Fiberglide
19
2
Guide block pin bushing
Steel + Fiberglide
20
4
Sliding block seat
Steel + Fiberglide
21
2
O-ring
NBR rubber
Figure 45
Scotch yoke mechanism heavy duty version
(minimum performed cycles* = 1.00.000)
NOTES:
* Recommended spare parts
** Cycles performed by actuator in a 25 years expected lifetime - the minimum performed cycles are
guaranted by Biffi based on service conditions listed:
-
All the valve required torques have to be lower than actuator max operating torque (MOT).
-
The ratio between valve required running torque and actuator max operating torque (MOT) has to be > 1.5.
-
The actuator mechanism has to be inspected, lubricated, seals and gaskets have to be replaced after
each 200.000 cycles.