The most powerful pump for its size. 5-chamber on-demand diaphragm pump rated at 60 PSI and 7.0 GPM with ½" FNPT ports. Built for agricultural chemical, industrial, and sprayer applications. Made in the USA. Not for potable water use.
The Remco Fatboy Series is engineered for demanding industrial and agricultural environments where most pumps fall short. Purpose-built to maximize the output of all five diaphragm chambers, the Fatboy is paired with a high-torque, completely sealed motor that delivers 7.0 GPM at 60 PSI — making it the highest-performing 12V sprayer pump in its class.
The 90-5538-1E1-94A-SB is the on-demand configuration with ½" FNPT ports — the right choice for sprayer systems that connect directly to ½" threaded plumbing lines. On-demand control means the pump runs when a nozzle or valve is opened and shuts off automatically when flow stops, with no bypass return line required. Viton valves and a Santoprene diaphragm make this pump chemically compatible with most common herbicides, fertilizers, and insecticides.
⚠️ Important: This pump is NOT designed for potable water use. For freshwater RV or drinking water applications, see the Remco Rebel or PowerRV series.
Highest-performing 12V Fatboy on-demand configuration — maximum flow for boom sprayers and high-demand agricultural operations
Threaded female NPT inlet and outlet — direct connection to standard ½" plumbing without Quick Attach adapters
Viton valves and Santoprene diaphragm withstand herbicides, fertilizers, insecticides, and common ag chemicals
Sealed motor with IP65 ingress protection — dust-tight and protected against water jets in the field
The Remco 5518-2I1-94A-B Fatboy Series pump is not listed or approved for potable water use. It is designed exclusively for agricultural chemical, industrial, and non-potable fluid applications. Do not use this pump in any system where the fluid may be consumed by humans or animals. For drinking water or freshwater RV/marine applications, Remco's PowerRV or Rebel Series pumps should be used instead.
The Fatboy Bypass Series excels in high-demand fluid delivery systems, including: Agricultural & Chemical: • Boom and spot sprayers (herbicides, fertilizers, insecticides) • Agricultural chemical transfer and injection • Liquid deicing fluid delivery (calcium chloride, potassium acetate, brine) Industrial & Municipal: • Road maintenance and dust suppression • Equipment washdown and pressure cleaning • Snow pre-wetting and anti-icing systems • Liquid transfer in industrial environments
On-demand setup — pump runs when flow is open, stops when closed. No bypass return line needed. 1. Mount the Pump: Secure to a flat surface using the rubber noise-dampening base. Use mounting screws with washers — stop when heads just touch washers to preserve the rubber grommets. 2. Plumb the Ports: Thread ½" NPT male fittings (not included) into the inlet and outlet ports. Apply Teflon tape to all male threads and tighten firmly. Connect your inlet supply hose and outlet spray line. 3. Electrical Connection: Connect 12 AWG leads directly to your 12V battery or switched relay circuit. Protect the supply line with a 30 Amp fuse as close to the power source as possible. 4. Prime & Test: Fill the inlet line with fluid before starting. Run briefly to purge air, then check all connections for leaks at operating pressure. Note: A relay is recommended for most installations. Contact Remco at 1-800-228-2481 for wiring guidance.
In The Box: • 90-5538-1E1-94A-SB Fatboy On-Demand Pump • Noise-dampening rubber mounting base • Mounting hardware NOT Included (Will Need Separately): • ½" NPT male fittings and hose adapters • 30 Amp inline fuse and fuse holder • Relay (recommended for switched circuits) • Teflon thread tape • Hose, clamps, or additional adapters • Strainer / inlet filter (recommended to protect pump)
Download the Remco Fatboy Series Installation & Owner's Manual (PDF) Download the 5538-1E1-94A Spec Sheet (PDF) Download the Fatboy Series Product Flyer (PDF) Technical Support: Remco Industries Phone: 1-800-228-2481 remcoindustries.com
The 90-5538-1E1-94A-SB is covered by Remco Industries' 1-Year Limited Manufacturer's Warranty from the date of manufacture (or 1 year from date of purchase with proof of purchase). Remco will repair or replace, at their discretion, any unit found defective in materials or workmanship under normal use. Warranty does NOT cover: • Misuse, abuse, misapplication, or external damage • Products altered outside the Remco factory • Normal wear, brush wear (may be limited to 1,000 hours), or appearance • Pumps not compliant with Remco Engineering Standards Warranty returns require a Return Material Authorization (RMA) number. Contact Remco prior to returning any product.
All Fatboy configurations share the same 5-chamber diaphragm design, Viton valves, Santoprene diaphragm, run-dry capability, and Made in USA construction. The "1" in the model number indicates Demand control; "2" indicates Bypass. The "E" prefix indicates 60 PSI; "I" indicates 100 PSI. FNPT port variants use the 5538 model prefix.