Specifications

Installation 00-02-0175 page 3 of 6
REPLACING AND INSTALLING THE DVOA ASSEMBLY
1. Block off and bleed the instrument gas pressure supply to the
L1200NDVO.
2. Remove the tubing between the L1200NDVO and the
separator dump valve, and remove the supply gas tubing
(regulator [-R] if used).
3. Remove the L1200NDVO from the vessel (optional).
4. If the L1200N was removed from the vessel, mount it in a
suitable vise on a work bench (if possible).
5. Using the proper tools, disconnect the Inlet, Outlet and
Exhaust fittings from the existing DVO (see fig. 1). You will
re-connect these to the new DVOA in a later step.
NOTE: The following steps must be done with the DVO in the
upright position (on top of the L1200N).
6. Remove the L1200N cover (this will aid with the alignment
of the new DVOA Valve Bushing). The use of a strap
wrench or a pipe wrench may be needed.
7. Insert the new Valve Bushing through the new DVOA (see
fig. 2). The markings on top of the DVOA must be facing
up. This will be needed in step 9.
8. With a 3/4” hex wrench loosen the existing DVO, valve
stem, and static seal (see fig. 3). Once the assembly is
loosened, VER
Y CAREFULLY use needle nose pliers to
hold the Valve Seat Assembly in place. Remove the existing
DVO making sure the Valve Seat Assembly inside the
L1200NDVO is aligned and straight (see fig. 4).
9. Holding the Seat Assembly up with the needle nose pliers
inside the L1200NDVO body, place the tip of the new
DVOA valve bushing through the spring and into the hole in
the center of the valve seat, and tighten the valve bushing.
The Valve Seat Assembly should be able to move freely up
and down after the bushing has been tighten. The DVO red
button must face away from the vessel.
10.With the new DVOA aligned over the hex on the L1200NDVO
body, tighten the Valve Bushing using the 9/16” hex wrench.
You may need to hold the DVOA while tightening the Valve
Bushing to keep it from rotating (see fig. 5).
11.If the L1200N is in the vise, operate the float and inspect for
smooth and proper operation of the Valve Seat Assembly.
12.Replace the L1200NDVO cover (see fig. 6).
13.Using the appropriate tools re-install the Inlet, the Outlet and
the Exhaust fittings to the new DVOA (see fig. 5).
14 If the L1200N was removed from the vessel re-install it at this
time.
15.Modify existing or install new tubing to connect the Inlet, the
Outlet and Exhaust fittings.
When replacing/installing the old style DVO assembly with the new style (DVOA), tubing and fitting modifications are required. We suggest
removing the L1200NDVO/DVOR from the vessel. Relieve pressure from the vessel or use block valves before removing the L1200NDVO/DVOR.
CAUTION:
MMAAKKEE SSUURREE tthhee VVaallvvee SSeeaatt AAsssseemmbbllyy iinnssiiddee
tthhee LL11220000NN rreemmaaiinnss iinn ppllaaccee aafftteerr rreemmoovviinngg tthhee DDVVOO..
NOTE: Clean,dr
y instrument quality gas should be used.
Use of filters will improve service life and reliability.
Figure 1
Exhaust
Valve Seat
Assembly
Valve Seat
Assembly
Inlet
Inlet
Outlet
(opposite side)
Outlet
Figure 3
Figure 4
Figure 5
Figure 6
Inlet
Inlet
Exhaust
Exhaust
L1200N
Cover
Valve
Bushing
Figure 2
New DVOA
New DVOA
Tools Needed: Strap or pipe wrench; 3/4” Hex wrench; 9/16” hex
wrench; needle nose pliers; tubing cutters and benders and the
appropriate tools for the fittings.
Replacing and Installing the DVOA
Assembly For Models L1200NDVO &
L1200NDVOR
Old DVO
New DVOA
DISCONTINUED