Medium Pressure DELTA 75 Pump w/Gear Reduction for 1” Shaft Gas Engine

The Udor DELTA 75 model D75GR1 is a 3-cylinder, medium-pressure diaphragm pump designed for reliable fluid transfer in demanding environments and heavy-duty applications, including car wash chemical delivery, hydrostatic testing, and equipment cleaning. It features an internally manifolded anodized aluminum construction with liquid handling parts made of anodized aluminum and stainless steel. This design provides reliable corrosion resistance and long-term durability in demanding spray applications. This pump delivers a maximum flow rate of 20 GPM and a maximum pressure up to 560 PSI. Operators will appreciate the transparent oil sight gauge for rapid maintenance checks and the robust body that withstands harsh conditions.

Key Benefits

• Corrosion Resistance: Built with internally manifolded anodized aluminum construction and stainless steel liquid handling parts to withstand harsh wash environments and chemical applications.
• Fast Oil Level Checks: A transparent oil sight gauge allows technicians to quickly verify proper lubrication levels and check for oil discoloration without removing any caps.
• Consistent Flow Rate: Rated for up to 20.0 GPM and 560 PSI, ensuring ample volume and pressure to keep your equipment running without starvation.
• Versatile Drive Options: Available in universal, gear reduction, and PTO configurations that integrate seamlessly with compatible feed systems. Note: The D75GR1 has the gear reduction system.

Specifications

• Manufacturer: Udor
• Manufacturer Product Number: D75GR1
• KR Product Number: UDD75GR1
• Maximum Flow Rate: 20.0 GPM (79.0 l/min)
• Maximum Operating Pressure: 560 PSI (38 bar)
• Maximum Speed: 550 RPM
• Inlet Port: 1-1/4" Hose Barb
• Outlet Ports: (2) 1/2" Hose Barb
• Bypass Port: 3/4" Hose Barb
• Piston Diameter: 60 mm
• Crankshaft Stroke/Code: 17.0 mm / G
• Drive Option: Gear Reduction for 1” Shaft Gas Engine,
• Dimensions: 13.5" L x 14.0" W x 12.0" H
• Diaphragms: GREENTECH standard (Buna-N optional)
• Recommended Oil: 40 oz. of Udor Lube 40W Premium Pump Oil
• Acceptable Alternative Oil: 30W non-detergent or 15W-40 non-detergent oil
• Applications:
  • Car Wash
  • Horticultural
  • Agricultural
  • Lawn Care
  • Nursery
  • Pest Control
  • Turf Spraying Applications
  • Aircraft De-Icing
  • Hydrostatic Testing
  • Cleaning Applications

When to Choose Buna-N Diaphragms Over Greentech?

Buna-N is an optional material for Delta 75 pumps and is preferred in applications where additional chemical resistance is critical. Select Buna-N diaphragms when working with extremely harsh chemicals or service fluids that require enhanced resistance to chemical attack beyond the standard Greentech diaphragms.

Quick Reference Service Parts

When sourcing replacement components for the DELTA 75, use exact OEM part numbers to guarantee fit and material compatibility. Here are some recommended kits of commonly replaced parts and a complete repair kit:

• Complete Repair Kit: 8700.75CK
• Diaphragm Kit (GREENTECH): 6062.E4
• Valve Kit: 6062.E6
• Diaphragm Bolt / Washer Kit: 6062.48
• Regulator Repair Kit: 6062.53

Udor DELTA 75 Drive Configurations

When replacing an existing pump or building a new system, selecting the correct drive configuration is critical for compatibility. All specifications, except for the drive configuration, are identical across models. Udor offers the DELTA 75 in three models:

• DELTA 75 VA: Features a Universal VA Drive Face with mounting rails. This is the standard configuration, weighing 46 lbs.
• DELTA 75 VAGR1: (Selected Configuration): Equipped with a gear reduction specifically designed for a 1” solid keyed shaft gas engine (8-20 HP). This configuration weighs 58 lbs. Ensure the gearbox is filled to the center of the sight glass with 90 wt. Gear lube before operating.
• DELTA 75 TSVA: Features a Universal VA Drive Face paired with a 1-3/8” 6-Spline Male PTO shaft and bolts. This configuration weighs 46 lbs.

Essential Plumbing and Installation Guidelines

Proper installation prevents premature pump failure. Udor diaphragm pumps are positive displacement pumps and require a pressure relief valve or pressure regulating valve to be installed on the pump or in the discharge plumbing. A secondary safety pop-off valve is also highly recommended to prevent property damage or system blowouts. See the attached manual for even more installation instructions and best practices.

Inlet and Suction Line Requirements

Never run the pump with a starved suction. A starved suction due to a closed suction valve or a clogged strainer will cause premature failure of the pump diaphragms. To ensure proper feed:

• Use filter screens between 10 and 20 mesh on the inlet side of the pump. Never use a fine filter screen on the inlet side of a diaphragm pump.
• The recommended minimum feed tank size is 6-10 times the maximum GPM output rating. For the 20 GPM DELTA 75, this means a minimum feed tank size of 120 to 200 gallons.
• Keep the suction hose ball valve open whenever the system is operating.
• Ensure each pump is fed by its own separate feed line. Never feed multiple pumps with one common feed line.

Bypass Line Requirements

The bypass line routes fluid when the discharge flow is shut off.

• Bypass hoses must remain open and unrestricted at all times.
• Never install an agitator or ball valve on the bypass hose. Use soft hose only.
• Keep the bypass line as far away as possible from the suction hose line inside the tank to prevent aeration or cavitation of the fluid being pumped.

Pulsation Dampener and Recommended Settings

Diaphragm pumps, by nature, have some pulsation. The pulsation dampener reduces pulsation by providing a cushion of air to bump against. The rubber bladder separates the air cushion from the pumped chemical solution.

• Set the pulsation dampener to 20% of your system's working pressure. For example, if your pressure is set at 100 PSI, the dampener should be set at 20 PSI.
• 20 PSI is the absolute minimum pulsation dampener pressure. Do not run the pump with less than 20 PSI in the dampener.
• Air supply can be from a compressor or a manual type pump.
• Always shut down the pump before adding air or checking pressure.
• It is possible to lose 5-10 psi when checking pulsation dampener pressure.

Routine Maintenance Procedures

Establishing a strict maintenance schedule greatly adds to the pump's longevity. The crankcase oil plays a dual role: lubricating moving parts and supporting the diaphragm hydraulically during each pressure stroke.

Recommended Maintenance Schedule

• After Each Use: Flush the pump with clean water to prevent chemical buildup. Most diaphragm “attacks” occur when chemicals are left sitting in the pump. This helps extend the diaphragm's longevity.
• After First 50 Hours: Perform an initial oil change to clear out any break-in particulates.
• Every 500 Hours (or Season's End): Perform a full oil change and replace the diaphragms. Inspect pump valves and check valves for spring fatigue and seat wear.
• Every 1000 Hours: Replace the internal valves completely.

Note: For heavy-duty purposes, Udor recommends more frequent maintenance intervals.

Oil Change Process

1. Remove the oil drain plug located at the bottom of the pump, along with the oil fill cap.
2. Once drained, reinstall the drain plug.
3. Fill the pump with 40 oz of Udor Lube premium pump oil (or SAE 30W non-detergent / 15W-40 oil) to the recommended mark on the oil reservoir or on the sight glass.
4. Rotate the crankshaft manually while filling to eliminate trapped air pockets.
5. Run the pump for five minutes under a "no-load" condition or in full bypass to evacuate remaining air pockets from the diaphragm cavity.
6. Turn the pump off and recheck the oil level.

Winter Storage and Anti-Freezing

Here is how to protect your Udor DELTA 75 from freezing conditions. Do not run the pump with frozen fluid.

1. Flush the pump with clean water.
2. With the tank empty and suction/discharge valves open, run the pump for exactly one minute to ensure complete drainage of the pump heads and lines.
3. Re-circulate anti-freeze and water at low pressure only. Leave it in the system.
4. When restarting, purge all anti-freeze from the pump and system at low pressure only. Anti-freeze will foam under high pressure, which can severely damage the pump and pressure regulator. This will void Udor's warranty.

Note: If a spray gun is installed, circulate anti-freeze through the hose and spray gun, directing it back into the tank lid to clear or dilute residual water. Depending on hose length and tank size, more than one gallon of anti-freeze may be necessary to safeguard the system against freezing.

Troubleshooting Common Issues

Low, No, or Inconsistent Pressure When Relief Valve Is Open to Boom or Gun

Causes:

1. Plugged filter restricting flow
2. Suction hose obstruction
3. Collapsed suction hose inside or outside the tank, restricting flow
4. Pump drawing air through suction line hoses or fittings
5. Pressure relief valve stuck or worn
6. Excessive tank foam due to low tank volume
7. Nozzle volume is greater than pump capacity
8. One or more pump valves/check valves are not seated properly

Remedies:

1. Clean filter screen
2. Clear obstruction
3. Replace the collapsed hose
4. Examine hoses and fittings, ensure an air-tight fit and no leaks
5. Repair or replace the relief valve
6. Refill tank
7. Reduce the nozzle orifice size or the number of nozzles used
8. Clean or replace pump valves/check valves

Pressure Gauge Shows Unstable Readings / Excessive Pulsation

Causes:

1. Pulsation dampener pressure too low or too high
2. Pump drawing air through suction line hoses or fittings
3. Plugged filter restricting flow
4. Air is not entirely evacuated from the pump cavity

Remedies:

1. Adjust pulsation dampener pressure (refer to pump operation sheet)
2. Examine hoses and fittings, ensure an air-tight fit and no leaks
3. Clean filter screen
4. Run the pump with an open discharge to totally evacuate air

Pump Does Not Draw Water

Causes:

1. Pump drawing air through suction line hoses or fittings
2. Plugged filter restricting flow
3. One or more pump valves/check valves are seating improperly

Remedies:

1. Examine hoses and fittings, ensure an air-tight fit and no leaks
2. Clean filter screen
3. Clean or replace pump valves/check valves

Milky Pump Oil or the Oil Plug Pops Out

Cause:

1. One or more diaphragms have ruptured

Remedies:

1. Replace all diaphragms
2. Clean filter screen

WARNING: This product can expose you to chemicals including Lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm (For more information go to www.p65warnings.ca.gov).