Nexen EN40-2B 912004 - Manual (Page 8)

(8) FORM NO. L-20097-F-0605
MAINTENANCE
FIGURE 15
There is no scheduled maintenance required for Nexen’s EN40 Electro-Pneumatic Convertor.
TROUBLESHOOTING
OPERATIONAL CHECK
1. Remove Gauge Port Plug, and install a suitable
air pressure gauge.
2. Apply Psup to inlet port (See Table 1).
CLEANING FIXED ORIFICE
NOTE: If dirt or foreign particles are present in Fixed
Orifice, check condition of Pre-filter and Coalescing
filter. These filters must be kept clean and properly
maintained to prevent clogging of Fixed Orifice.
1. Remove Fixed Orifice Housing (See Figure 14).
2. Remove O-ring and Orifice Plate (See Figure 15).
3. Clean Fixed Orifice Housing Air Passage.
4. Passing a thin wire through hole in Orifice Plate,
clean Orifice Plate Air Passage.
CAUTION
Do not use cleaning solvents to clean o-
rings. Clean o-rings with a clean dry cloth,
then apply a thin coat of o-ring lubricant
to the o-rings.
5. Install Orifice Plate and clean O-rings into Fixed
Orifice Housing.
6. Install Orifice Housing onto EN40.
FIGURE 14
PARTS LIST
3. Vary electrical signal to “EN40” within the range of
4-20mA, DC.
a) If pressure does not vary directly with signal,
reverse electrical leads.
b) If pressure is slow to react to changes in
signal, clean Fixed Orifice.
Fixed
Orifice
Housing
O-ring
Orifice
Plate
Item Description EN40-1A EN40-1B EN40-2B EN40-1D
1 Upper Diaphragm Assembly 2720 2720 2720 2720
2 Lower Diaphragm Assembly 2721 2722 2722 2723
3 Orifice Plate 2662 2662 2662 2662
4 Coil Assembly with Poppet 2666 2666 2666 2666