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1.6.3 Choice of pressure converter and setpoint springs
In order to choose the correct pressure converter and setpoint springs for a required
threshold value, proceed as follows:
The lower threshold value is only determined by the force of the minimum spring;
Choose the pressure converter for the required threshold value from table III;
When you have a choice of 2 pressure converters, choose the pressure converter
with the largest sensing surface (SM2 is the smallest, SM90 is the largest);
Now select from table IV the relevant setpoint spring for the minimum threshold value
of the pressure converter you have just decided on;
The maximum threshold value is determined by means of the force of the minimum
and maximum spring. In order to determine the maximum threshold value, the
minimum threshold value should be deducted from the maximum. The pressure
difference determines the selection of the maximum spring;
Using the calculated pressure difference, you select from table IV the setpoint spring
of the maximum threshold value.
Example of selection of the setpoint springs for the minimum and maximum
threshold value
Given:
Minimum threshold value 2 bar
Maximum threshold value 22 bar
Calculate the pressure difference between maximum and minimum threshold value:
Result: 22 bar - 2 bar = 20 bar.
Choosing the pressure converter and setpoint springs:
acc. table III, pressure converters SM1.4-A and SM1.9-A are suitable. The SM1.9-A
has the larger diaphragm surface and is to be chosen;
in table IV we find for a lower threshold value of 2 bar the black setpoint spring with a
pressure range of 1.4 to 3.8 bar;
for the maximum threshold value of 20 bar we find the brown setpoint spring with a
pressure range of 15.5 to 21.5 bar.
1.7
Type indication (example)
Type
Nominal diameter (in inch or DN)
Pressure stage (ANSI)
HON HSV086 - .." - ANSI 600 -
© 2017 Honeywell International Inc
Operation and maintenance manual HON HSV086
9
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