Dresser Masoneilan SVI II AP, Инструкция по эксплуатации

Страница: 29 / 160

DRAFT 6/8/10
17
Magnet Orientation on Rotary
Installation and Set
Magnet Orientation on Rotary Valve Shafts
The same mounting hardware is used for Models 35, 30 actuators. For each actuator type
the magnetic coupling must be properly oriented to the active sensing angle of the
positioners Hall Effect sensor. The active range of the Hall-Effect sensor is plus⁄minus 70°
from the null magnet axis. If the total valve travel is less than 60°, allowing a margin for
tolerances, the best accuracy is achieved by mounting the magnet with the axis vertical in
the valve-closed position. Note the location of the magnets in the ring of the magnet
holder. The axis of the magnets is the line through the centers of both magnets. Mount
the magnet holder with the magnet axis vertical on the 35, 30 when the valve is closed. If
travel of the valve exceeds 60°, the magnet must be assembled to the rotary valve shaft
so that the magnet axis is vertical when the valve is at mid-scale.
Dismantling the SVI II AP from Rotary Valves
WARNING
Before carrying out any work on the device, power off the
instrument or make sure that the device’s location conditions
for potentially explosive atmosphere permit the safe opening
of the cover.
To remove the SVI II AP positioner from a rotary valve perform Steps 1 - 8 on page
page 10 in reverse.
Mounting the SVI II AP on Reciprocating Valves
This section describes the procedure for mounting the SVI II AP on Reciprocating Valves
(using Masoneilan’s 87⁄88 Multi-Spring actuators as an example).
Tools required:
q 7⁄16" Combination Wrench (2 required)
q 3⁄8" Combination Wrench
q 1⁄2" Combination Wrench
q Phillips Head Screw Driver
q 5 mm Hex Key Wrench
Mounting the SVI II AP on a Reciprocating Actuator
1. Ensure that the lever is pinned to the magnet assembly and held securely by an M5
flat head screw to ensure that the magnet axis is vertical when the lever is in the valve
closed position. Tighten the lever screw securely.
2. Mount the SVI II AP reciprocating mounting bracket to the actuator using two (2) 5⁄16
- 18 UNC cap screws. The mounting location of the bracket depends on the size and
stroke of the actuator. Refer to Figure 9 on page 19 and Figure 3 on page 19.