Orange Research 1204 Series User manual

GN128-Explosion-Proof Piston Rev. 0 Orange Research Inc. Page 1 of 2
INSTRUCTIONS
Series 1204
DIFFERENTIAL PRESSURE INSTRUMENTS
Piston Sensor –Explosion Proof
Your new Orange Research Differential Pressure Instrument is a
rugged instrument featuring simplicity of design to provide
dependable and efficient service. Because it is an instrument it
should be handled with care. Read all instructions carefully
before attempting to install the instrument.
CAUTION: Do not exceed maximum operating pressure
listed on instrument label. Use only fluids compatible with
wetted parts, including seals.
HOW IT WORKS
The instrument operates on the difference between two
pressures (delta-P). The sensing element is a spring biased
piston which moves linearly in proportion to the difference
between two basic pressures. A magnet on the HI pressure side
of the piston assembly moves with the piston and rotates a
follower magnet located adjacent to the pressure cavity. The
gauge pointer is located at the end of the rotary magnet shaft and
rotates with the magnet to provide gauge readings proportional to
differential pressure variations. This is accomplished by the
coupling forces between two adjacent magnets through a solid
wall.
SWITCHES: A secondary magnet, located in the extension tube
also moves with the pressure sensor. Reed switches, mounted
externally on the pressure extension tube are actuated when the
field of the secondary magnet interacts at a preset point with the
reed switch armatures.
NOTE: This instrument will provide 2% accuracy full scale.
INSTALLATION
Check instrument and identify the HI and LO markings. HI
identifies the high pressure port; LO the low pressure port. If
instrument is installed backwards, it will neither operate nor be
damaged. The instrument can be line mounted, pipe mounted or
panel mounted.
Installation Notes:
These piston sensor instruments are design for liquid
service only…use in gas systems will result in erroneous
readings due to excessive piston bypass
Do not mount directly to steel surfaces…this could affect
the magnetic sensors…mounting 1 inch from ferrous
metals is recommended
If there is particulate in the line, insert a screen (approx.
100 micron) to block the particulate from becoming
lodged in the instrument
Do not install on systems for highly viscous fluids or
where the fluid may become hardened over time
Do not install on systems with iron in the fluid…the iron
can become attached to the magnetic sensors
Install the unit above the process lines to prevent
particulate from settling in the instrument
Before installation, refer to our Specification Sheets (on
our website) to identify instrument component materials
& double check for chemical compatibility
MAINTENANCE
Other than replacing a broken lens, there is only one area where
this instrument may need attention. Erratic pointer or switch
action may indicate that cleaning is required. For cleaning:
1. Remove the unit from service.
2. Remove end cap with a 1” spanner wrench.
3. Remove the range spring and the piston/magnet assembly.
BE CAREFUL NOT TO LOSE STACKING SPACERS, IF
ANY.
4. Clean parts in a solvent solution after removing the “O”-ring
seals from the end caps since some solvent will attack the
seal material.
5. It is good practice to replace the “O”-ring seals while the
instrument is dismantled. DO NOT ATTEMPT TO REMOVE
THE TEFLON PISTON SEAL FROM THE PISTON. If piston
seal is damaged order a new piston/magnet assembly.
To reassemble:
1. Replace the piston assembly. CAUTION: Do not bend the
stainless steel wire which connects the secondary magnet to
the piston assembly.
2. Make certain that the spacers are seated in the piston spring
pocket and reinsert the spring.
3. Reassemble the end cap and tighten. NOTE: Be certain that
the head of the spring is seated in the end cap spring
pocket. The unit is now ready for service.
LENS REPLACEMENT: To remove a threaded retaining ring,
unscrew the retaining ring, or to remove the snap ring, pry out the
ring with a small screwdriver. Remove the glass chips, insert
new lens and reinstall the snap ring and threaded ring. For snap
rings locate the ring joint at the bottom of the gauge.
POINTER REPLACEMENT: (probably damaged when lens was
broken). Remove Threaded ring or snap ring as previously
described and clean out glass chips. Remove old pointer with
pointer puller or two small screwdrivers opposite each other
under pointer hub. Pry off evenly being careful not to bend the
pointer shaft. Install new pointer dead on zero. Re-install lens, as
described under Lens Replacement.

GN128-Explosion-Proof Piston Rev. 0 Orange Research Inc. Page 2 of 2
WARNING: This product contains Nickel, a chemical known to the State of California to cause cancer. For more information
go to: www.p65warnings.ca.gov
SWITCH ADJUSTMENT
Reed switch set points are field adjustable. On Indicating Switches, the
reed switches can be adjusted over the top 80% of the gauge range. On
Switch models the reed switches can be adjusted over the range shown
on the instrument label.
Minor Switch Adjustments*
To change the switch adjustment:
1. Unscrew the cover on the electrical enclosure. This cover will be
facing the front of the instrument on the lower section of the
assembly.
NOTE: Panel mounting reversed.
2. Switches can now be adjusted by turning the adjustment screws
located above the terminal strips on the switch saddle assembly.
A. Clockwise rotation will increase the switch set point.
B. Counter-clockwise rotation will decrease the switch set
point.
3. Replace the cover.
* For major switch adjustments, contact Orange Research
SWITCH REPLACEMENT:
1. Unscrew the cover of the electrical enclosure, remove the cover.
2. Disconnect the switch wires from the terminal block. Note the
locations of the wires.
3. Remove (2) screws that fasten the terminal block bracket. Remove
the bracket (Relay models do not have this bracket).
4. Loosen, BUT DO NOT REMOVE, the (2) switch adjustment plate
retaining screws (Relay models will have 3 or 4 retaining screws).
Turn screws 3 revolutions counter-clockwise. Removal of retaining
screws will make re-assembly more difficult.
5. Pull up on the switch adjustment plate and remove the switch & gear
assembly (it may be necessary to loosen the saddleblock lock screw
and slide the entire saddleblock assembly down towards the conduit
connections).
6. Insert the new switch & gear assembly into the saddleblock.
7. Tighten the saddleblock lock screw, if necessary.
8. Tighten the (2) screws on the switch adjustment retaining plate
(Relay models will have 3 or 4 retaining screws).
9. Re-assemble the (2) screws that hold down the terminal block
bracket.
10. Connect the switch wires to the terminal block.
11. Adjust switch as necessary following the SWITCH ADJUSTMENT
procedure.