8
Operation
Required Tools for Operation
No tools are required for changing the set pressure on a standard regulator.
Points of Attention Before Operation
CAUTION
The product can be hot or cold, depending on the environmental temperature and the process
media temperature. Take the necessary precautions before operating or touching the product.
- Stopping flow through the regulator by closing a downstream shutoff valve may result in a rise in outlet
pressure above the set pressure. This is usually referred to as “lock-up”. This phenomenon does not
indicate a problem with the regulator.
- A decrease of the flow rate may result in a rise of the outlet pressure. An increase of the flow rate may
result in a fall of the outlet pressure. This is usually referred to as “droop”. This phenomenon does not
indicate a problem with the regulator.
- A decrease of the inlet pressure may result in a rise of the outlet pressure. An increase of the inlet
pressure may result in a fall of the outlet pressure. This is usually referred to as “inlet dependency” or
“Supply Pressure Effect (SPE)”. This phenomenon does not indicate a problem with the regulator.
Adjusting the Set Pressure
- The set pressure is the desired outlet pressure of the regulator.
- To set the regulator, ensure that the supply pressure is greater than the required set pressure but does
not exceed the maximum rating of the regulator.
- Excess outlet pressure will self vent through the port in the side of the regulator.
1. Ensure there is zero pressure in the dome.
2. Steadily open the supply valve to allow inlet pressure to the regulator.
3. The set pressure is controlled by altering the dome pressure. Increasing the dome pressure raises the set
pressure while decreasing the dome pressure lowers the set pressure.
NOTICE
The outlet pressure of the regulator is sensitive to changes in the dome pressure. Every change
to the dome pressure will result in an outlet pressure change equal to the dome pressure
change, multiplied by the ratio of the regulator. For example; with a 1:70 ratio regulator a rise of
14.5 psig (1 bar) of the dome pressure will result in a rise of 1015 psig (70 bar) of the outlet
pressure.
4. To obtain the most accurate set pressure, final adjustment must be made while increasing the set
pressure. If the desired outlet pressure is exceeded, reduce the pressure below this value then increase
up to it.
5. Fully open any downstream valve to allow full flow during operation.
6. Once under flow conditions make any final set pressure adjustments per steps 3 and 4 if required.
