Testing For Leaks; Timer, Pressure Switch, And Pressure Gauge; (Purging System) Blower; Blower Installation Requirements - Bennett LNG Series Installation Manual

Bennett LNG Series Installation Manual

Testing For Leaks

Once the dispenser is mounted and anchored onto the island, it is important to check all fittings prior to testing them
for leaks. Refer to Figures 4 and 6 for tube locations on the previous pages.
Follow these steps to test the inlet instrument air "D" for leaks:
1. Spray the inlet instrument air "D" connections with a solution of soapy water.
2. Pressurize the line to 100 PSI for five minutes.
3. Inspect for bubbles forming around the connections.
If at any time, there is evidence of a leak, remove pressure from the line, repair any leaks present, and restart the test
from the step one.

Timer, Pressure Switch, and Pressure Gauge

A timer & relay, gauge, switch, and blower port that are shown in Figures 7, 8, and 9 are used to control the power of
the dispenser. If the pressure switch detects less than .15 inches of water in the electronic enclosure then the power
will be removed from the dispenser until the pressure differential returns to .15 inches of water. During the delay, the
volume of air in the cabinet will be circulated at least 4 times and then power will be restored to the dispenser.
Blower Port
Figure 7 – Blower Port

(Purging System) Blower

It is required for the electronic enclosure of the dispenser to maintain a minimum pressure differential of 0.15 inches
of water at all times. To achieve this, a blower must be installed and attached to the port at the bottom of the vapor
barrier as shown in Figure 7. The blower must be installed at least 15 feet away from an unclassified area. To connect
the blower to the dispenser, use the 2-inch (50 mm) PVC nipple from the footprint of the dispenser to the port at the
bottom of the flame deck.

Blower Installation Requirements

CAUTION: Prior to performing work, the environment must be cleared of any hazardous gases.
The purge air supply pipe shall be 2-inch (50 mm) schedule 40 PVC.
•
The maximum lineal length of piping from blower to the dispenser shall be 100 feet.
•
The maximum angle of bends in the piping run shall be no more than a total of 720 degrees.
•
A dispenser shall have its own independent purge air supply.
•
A filtration system shall be provided such that the air supply is "essentially free of contaminants" and meets
•
MERV 13 levels for contaminants.
The filter shall have a minimum Airflow capacity of 100 CFM
•
Piping Installation
Timer & Relay
Figure 8 - Timer & Relay
11
Figure 9 – Pressure Switch and Gauge
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Piping Installation