201-G00 Page 3/8
INSTALLATION
MOUNTING THE AIR/RELIEF VALVE
1. Remove the pump relief valve cap (1) and turn the adjusting
screw (2) counterclockwise to relieve spring tension,
reference the pump maintenance manual.
2. Remove and discard the pump’s four relief valve cover bolts
(5 & 5C). Remove the cover assembly (4), spring guide (7),
spring (8), and gasket (10). Clean and inspect the gasket
surfaces, repairing as necessary.
3. Install a new gasket (10).
NOTICE:
The relief valve spring must be confined between the boss
on the relief valve (9) and the boss on the piston (11A).
4. Attach the Air Valve assembly to the pump using the four
new bolts provided (5 & 5C). Ensure the relief valve spring
is seated in the piston boss. Position the valve cover (4) so
that the air inlet pipe hole is accessible to attach the air line.
5. Torque the air valve mounting bolts as indicated in Table 1.
PUMP MODEL TORQUE * - lbs ft (Nm)
TXD2.5, TXD1225, TXH3
TXD3, TXD1230 19 – 25 (25.8 – 33.9)
* Torque bolts in an alternating pattern.
Table 1
AIR/RELIEF VALVE ADJUSTMENT
NOTICE:
Maintenance shall be performed by qualified technicians
only, following the appropriate procedures and warnings
as presented in this manual and the appropriate pump
installation, operation, and maintenance instructions.
Hazardous pressure
can cause serious
personal injury or
property damage.
Failure to relieve system pressure prior
to performing pump service or
maintenance can cause personal injury
or property damage.
NOTICE:
If the air valve retaining ring (11F) is removed, and the
jam nuts (11E) turned out beyond the retaining ring, the
piston (11A) will not seal, allowing air to leak to the
atmosphere.
The Blackmer Air Valve low and high pressure settings are
adjustable within a specific range to suit the engine operating
speed and operating conditions. See Table 2. Attach a
suitable pressure gauge at the pump discharge gauge port
(73) to make the required air valve adjustments. Record the
air valve and pump operating pressures in the “Initial Air
Valve Settings” chart.
Discharge Pressure Setting / Range – PSI (bar)
Model TXD2.5, TXD1225,
TXH3 TXD3,
TXD1230
Pump Operating 100 (6.9) Maximum
Low 40-80 (2.8-5.5) 55-85 (3.8-5.9)
70-125 (4.8-8.6); 80-125 (5.5-8.6);
High 125 (8.6) Maximum – Do Not Exceed
Peak 15-25 (1.0-1.7) above normal
operating pressure
Table 2 – Blackmer Piston Air Valve Settings
LOW PRESSURE ADJUSTMENT:
The air valve low pressure adjustment MUST be set first.
NOTICE:
The air valve low pressure setting regulates the delivery
hose pressure when the nozzle is closed. Adjust the air
valve only high enough to open the flow sensing valve.
1. Adjustment MUST be made with the pump at normal idle
speed - 200 RPM minimum.
2. SLOWLY close the delivery nozzle, allowing the pressure
to be relieved inside the air valve cap.
3. Remove the air valve cap (1) and O-ring (88).
4. Turn the adjusting bushing (2C) clockwise to increase the
pressure setting, or counterclockwise to decrease the
pressure setting. Refer to Table 2 for setting ranges.
5. Install O-ring and air valve cap, tighten the cap securely.
6. Open and close the delivery nozzle several times to
ensure the correct setting.
Hazardous pressure
can cause serious
personal injury or
property damage.
Incorrect settings of the Blackmer air
valve can cause system component
failure, personal injury and property
damage.
HIGH PRESSURE ADJUSTMENT: Do not exceed
the maximum pressure listed in Table 2.
1. Adjustment MUST be made with the pump at normal
operating speed and with air pressure behind the air
valve piston.
2. Slowly close the delivery nozzle, allowing the pressure to
be relieved inside the air valve.
3. Remove the air valve cap.
NOTICE:
Always use a counter wrench (opposing wrench) when
tightening the jam nuts (11E). Always start with the jam
nuts turned all the way down, clockwise, against the
adjusting bushing.
4. Adjust the jam nuts counterclockwise to increase the
pressure setting or clockwise to decrease the pressure
setting, until the required high pressure setting is
achieved. See Table 2 for setting ranges.
5. Install the air valve cap securely.
6. Open the delivery nozzle and observe the pump’s
discharge gauge. Repeat steps 2-5 until required high
pressure setting is achieved.
7. After the final adjustment is made, ensure that the jam
nuts (11E) are tight. Inspect the air valve cap O-ring (88)
and replace as necessary.
NOTICE:
Where regulations require, holes in R/V cap (1) and
capscrew w/hole (5C) are used by the Weights and
Measures official(s) to apply a security seal or tag.
