Gas Shut Off Valve Electronics Enclosure
The electronics enclosure houses all of the circuitry and
battery power necessary to control the shut off valve in the gas meter. In order to protect the internal components
from moisture and potentially harmful environments the assembly is hermetically
sealed with a potting compound. After all components have been fully assembled
and sealed in the enclosure the entire assembly slides into an aluminum cup and
is secured in place with 3 screws.
Electronics enclosure in meter
The state of the art for the majority of gas meters is that
they do not contain shut off valves inside the meter, circuitry to control the
valves remotely or enclosures to house all of the circuitry.
On the top portion of the potting shell there is a tall RF
tower that is intended to properly position the circuit board for maximum RF
propagation. The elevated position of the board lessens the effect of potential
“RF” obstructions. There are 3 mounting screw holes used to mount the potting
shell into the mating aluminum cup. Around one of the 3 screw holes is a
circular rib used to protect the unit from unauthorized disassembly of the
unit. The circular rib accepts a small
plastic cap that covers over the mounting screw. The cap is pressed in place
and cannot be removed. The rib is referred to as the “vandal plug tower”.
each corner of the RF tower there are diagonal shaped ribs. These ribs are intended to prevent a gas
utility from mistaking the tower for a gas valve cock and installing a wrench
to try and twist it open or closed. The
interior of the potting shell contains features for locating 2 batteries and 2
circuit boards. Each battery has 3 points of contact to keep it in its proper
position. The circuit boards are held
inside the tower through friction between the shell and a piece of pre-attached
On the bottom of the potting shell the long walls are
rounded on one side and flat on the other creating a “half round” profile of
the part. On the rounded profile there are clearance notches to allow the
potting shell to fit within an aluminum enclosure. On the flat side of the potting
shell are a series of ribs used to secure a 7 pin connector assembly.