Install Drawing
UNLOADER SPECIFICATIONS
MODEL 7500S U.S. Measure Metric Measure
GPM .......................................... 0.5-6.0 GPM (2-23 L/M)
PSI............................................. 100-2000 PSI (7-140 BAR)
Inlet Port - Rear......................... 3/8" NPTF (3/8" NPTF)
Discharge Port - Front............... M18x1.0 (M18x1.0)
By-pass Port - Bottom............... 3/8"NPTF (3/8"NPTF)
Weight ....................................... 14 oz. (0.43 kg)
Dimensions................................ 3.0 x1.0x4.25" (76x25x108 mm)
ITEM P/N MATL DESCRIPTION QTY.
471 33949 NY Cap, Adjustment 1
472 32941 BB Hose Barb 1
33505 BB Barb, Fixed 1
473 33503 NBR O-Ring, Hose Barb 1
474 33500 S Spring 1
475 33946 BB Retainer, Ball Seat 1
476 33504 FPM O-Ring, Retainer 1
477 34620 SS Ball 1
478 33501 SS Spring, Tapered 1
479 32373 S Orifice, Injector (2.1mm) Standard 1
32374 S Orifice, Injector (2.3mm) 1
480 — BB Body 1
481 33481 BBNY Barb, Assy, Adjustable 1
(Inclds: 471,472,473,474,475,476,477,478)
— 33480 BB Barb, Assy, Fixed (Inclds: 472,476,477,478) 1
482 13969 NBR O-Ring, Body - 70D 1
Italics are optional items.
MATERIAL CODES (Not Part of Part Number): BB=Brass FPM=Fluorocarbon (Viton
®
)
NBR=Medium Nitrile (Buna-N) NY=Nylon S=304SS SS=316SS
CHEMICAL INJECTOR PERFORMANCE CHART
Optional Special Ported Chemical Injector for Unloader Mounting
Lo-Pressure Nozzle Rating Max. Chem. Draw Hi-Press Nozzle
Standard Injector (Maximum Downstream) (0 PSI) “Deduction” (Press.
Pump Model Orifice Size (Press for Injector) (Downstream) drop across Inj.)
2SF20 2.1 mm (7193) 100 PSI 50 oz/min 100 PSI
2SF22 2.1 mm (7193) 75 PSI 50 oz/min 100 PSI
2SF29, 2SF30 2.1 mm (7193) 225 PSI 50 oz/min 150 PSI
2SF35 2 3 mm (7194) 150 PSI 50 oz/min 150 PSI
CHEMICAL INJECTOR SPECIFICATIONS
Standard Optional
MODEL 7193 7194
Flow........................................... 3-4 GPM 4-5 GPM
Nozzle Orifice............................ 2.1mm 2 3mm
Hose Barb ................................. 1/4" 1/4"
Inlet Port.................................... M18x1.0 M18x1.0
Discharge Port........................... 3/8"NPTM 3/8"NPTM
Weight ....................................... 6.3 oz. 6.3 oz.
Dimensions................................ 2x1x3" 2x1x3"
OPERATION
A Regulating Unloader comes with each 2SF pump to provide system
pressure regulation and pump protection. For suction feed consult factory.
By-pass for the regulating unloader may drain to the ground, drain to a
reservoir or connect to the special 1/4" by-pass port on the underside of
the inlet manifold. A 3/8" flex ble hose and Thermo Valve (7090.40) are
recommended. DO NOT EXCEED 6 MINUTES in BY-PASS when Thermo
Valve is not installed.
Hi-Temp Units with special Hi-Temp seals do not use the by-pass hose
back to the pump inlet or the Thermo Valve. Use optional Dual Pressure
Switches and Mechanical Relay in Auto Shut Off Kits 34870 and 34871.
If unit is INFREQUENTLY USED OR PERIODICALLY STORED, seals
may become dry. System should be PURGED BEFORE OPERATION
(system liquid must flow through the pump without discharge restriction) to
assure full system pressure is reached.
Optimum performance of chemical injector occurs with a 35 ft. high pres-
sure hose and a minimum 3/8" I.D. The type of hose, extended lengths,
reduced I.D. and fittings may create back pressures in excess of the low
pressure nozzle rating and prevent the injector from drawing chemical.
Deduct hose friction loss from above low PSI Nozzle. Contact factory
for assistance with other options. Refer to Hose Friction Loss Chart in
the Service Manual for pressure loss with longer hose.
An optional, specially ported chemical injector may be mounted
directly to the discharge of the unloader. Remove o-ring, check valve and
spring from discharge fitting of unloader; insert into injector and thread into
unloader discharge port. Discard o-ring and discharge fitting. Refer to
the performance chart to determine the orifice size best suited to the
system flow. Chemical draw occurs under low pressure. Select the
Change Over Nozzle (32149), Adjustable Nozzle (32151), or Vari-Nozzle
(7930-7980) to permit the adjustment from low to high pressure.
For optimum performance when using a chemical injector, use a single
wire braid hose on the discharge line. Too flex ble a hose will prevent
the unloader from receiving the full pressure signal to activate the by-pass
mode.
For correct nozzle selection, read system pressure at the pump. DO
NOT READ SYSTEM PRESSURE AT THE HIGH PRESSURE GUN.
Incorrect pressure reading may result in: pump operation at excessive
pressures, inconsistent chemical draw, or possible damage to the pump
or unloader.
ITEM P/N MATL DESCRIPTION QTY.
402 540081 BB Cap, Hex Adjusting 1
404 31047 BB Nut, Locking (M18x1) 1
408 32094 STZP Spring, Coil 1
410 107672 BB Retainer, Spring 1
412 45694 S Stem, Piston (M5) 1
415 20184 PTFE Back-up-Ring, Piston Stem 1
416 14190 NBR O-Ring, Piston Stem - 70D 1
425 107673 BB Retainer, Piston 1
428 13969 NBR O-Ring, Piston Retainer - 70D 1
429 14759 NBR O-Ring, Body 1
430 107675 PTFE Back-up-Ring, Body 1
435 45696 BB Valve and Ball Assembly (M5) 1
436 107680 S Seat 1
440 — BB Body 1
441 13963 NBR O-Ring, Valve 1
442 13969 NBR O-Ring, By-Pass Fitting - 70D 1
443 541060 BB Valve, Check w/O-Ring 1
444 45924 S Spring - 85G 1
446 13969 NBR O-Ring, Discharge Fitting - 70D 1
455 45695 BB Fitting, By-Pass (3/8"NPTF) 1
460 107681 BB Fitting, Discharge (3/8"NPTF) 1
465 7090 By-Pass Hose (15"x3/8") 160°F 1
466 7090.40 By-Pass Hose w/Thermo Valve 1
468 32097 NBR Kit, O-Ring (Inclds: 415,416,428,429,430,441,442,446) 1
485 7140 BB Valve, Thermo 1
486 34600 BB Tee, T.V. Mount 1
487 — BB Nipple, T.V. Mount 1
Italics are optional items.
MATERIAL CODES (Not Part of Part Number): BB=Brass NBR=Medium Nitrile (Buna-N)
PTFE=Pure Teflon
®
S=304SS STZP=Steel/Zinc Plated