Operation - Siemens 599-06611 Technical Instructions

Technical Instructions
Document Number 155-758
June 14, 2019

Operation

Sizing
Page 8
Flowrite™ 599 Series High Pressure Close-Off Two-Way Valves 2-1/2 to 6-inch
Figure 3 shows the normally open valve in the open or full flow position and the normally
closed valve in the closed, or zero flow position. The actuator spring provides the necessary
force to hold the stem in the raised or normal position.
In the event of power failure, a spring return actuator returns the valve to its normal
position.
Non-spring return actuators will hold the last commanded position. See the Technical
Instructions of the various actuators for additional information.
The sizing of a valve is important for correct system operation. An undersized valve will not
have sufficient capacity at maximum load. An oversized valve may initiate cycling, and the
seat and throttling plug may be damaged because of the restricted opening. Correct sizing
of the control valve for actual expected conditions is considered essential for good control.
Some variables which must be determined are:
•
The water and 50% water-glycol solutions, are the controlled mediums.
•
The pressure differential that will exist across the valve under maximum load
demand.
•
The maximum capacity the valve must deliver.
•
The maximum line pressure differential that the valve actuator must close against.
See Tables 5 through 6, and Figure 2 for valve capacities and sizing selection.
Normally Open Normally Closed
Figure 3. Operation.
Flanged Iron Body, ANSI Classes 125 and 250
Siemens Industry, Inc.