Honeywell L404V specifications Location and Mounting L404F, Location and Mounting L404T,V

L404F,T,V PRESSURETROL® CONTROLLERS

IMPORTANT

When making pipe connections, use pipe dope sparingly to seal the joints; any excess dope may clog the small hole in the fitting and prevent the controller from operating properly.

Location and Mounting (L404F)

Locate the L404F where the ambient temperature will not exceed 66°C (150°F). The L404F can be mounted near the pressure gauge, at a remote location, in a fitting provided by the boiler manufacturer, or in a special mounting on low water cutoffs. The L404F should always be mounted above the water line in steam boiler applications.

NOTE: For accurate operation, supplemental heat should be added to installations where temperatures fall below -29°C (-20°F).

A steam trap must be connected between the L404F and the boiler (see Fig. 2) to prevent boiler scale and corrosive vapors from attacking the elbows or diaphragm.

Remote Mounting

Excessive vibration at the boiler may affect the operation of the L404F. In these cases, the L404F should be remotely located, subject to the following:

1.All piping must be suitable and properly pitched to drain all condensation back to the boiler.

2.The remote mounting must be solid.

3.A steam trap must be used at one end of the piping.

Boiler Mounting

If it is not convenient to mount the L404F adjacent to the pressure gauge, install a steam trap at the location recommended by the boiler manufacturer, then screw the device directly to the steam trap.

Location and Mounting (L404T,V)

Location

PRESSURE

PRESSURE GAUGE

CONTROLLER

TEE

	14026	1
4-1/2 TO 5-1/2	STEAM TRAP
	(SIPHON LOOP)
(114.3 TO 139.7)

NOTE: For most accurate operation, supplemental heat should be added to installations where the temperature falls below -20°F (-29°C).These controllers can be mounted at any location in the oil supply line, depending on the application. Typical locations are shown in Fig. 3. The low oil pressure controller should be located upstream from the safety shutoff valve(s). In a downstream location, there would be zero pressure when the burner is not running and the safety shutoff valve(s) is (are) closed. This could prevent startup or require manual reset every time the burner is started. The high oil pressure controller should be located as near to the burner as possible.

BOILER

11/4 IN. BLACK IRON PIPE WITH 1/4 - 18 NPT EXTERNAL THREADS ON BOTH ENDS AND 2-1/4 IN. DIAMETER LOOP.

M8934B

Fig. 2. Steam trap mounting.

Mounting

Mount the oil pressure controller directly on the main pipe. Insert a tee in the pipe line, and connect a pipe nipple of appropriate size to the tee (see Fig. 4). Screw the hexagonal fitting (1/4-18 NPT internal thread) of the pressure controller to the pipe nipple. To avoid leaks and damage to the case, use a parallel jaw wrench on the hexagonal fitting close to the pipe nipple. Do not tighten the pressure controller by hand by holding the case.

Pressure Gauge Mounting

To mount beside a pressure gauge, remove the gauge, and install in its place the steam trap with a tee on top. Mount the PressureTrol® unit and pressure gauge on the side of the tee by means of nipples and elbows (see Fig. 2).

Make all pipe connections in accordance with approved standards. Use only a small amount of pipe compound to seal the connection joints. Excess pipe compound may clog the orifice in the pipe fitting and prevent the controller from operating properly.

MAIN	STRAINER
OIL						ATOMIZER
LINE
MANUAL
SHUTOFF	OIL	LOW OIL	LOW OIL		HIGH OIL	MANUAL	TO OIL
VALVE	PUMP WITH	PRESSURE	TEMPERATURE	RECIRCULATING	PRESSURE		BURNER
	PRESSURE RELIEF	CONTROLLER		VALVE AND SAFETY	CONTROLLER	SHUTOFF
				SHUTOFF VALVE		VALVE
					ATOMIZING MEDIUM
					(AIR OR STEAM)		M17861

Fig. 3. Typical locations of pressure controllers in an oil burner system.

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