The Model 121A fuel/water separator is a diesel fuel/water separation and filtration vessel that employs Kaydon Filtration coalescing technology to separate water from diesel fuel.  In addition to removing water, the coalescer element provides a particulate filtration layer to remove harmful particulates, along with providing protection for the coalescer.  The 121A vessel is constructed of durable, rugged, heavy-duty aluminum. The Model 121A is designed to provide filtration and water removal for diesel fuels (Diesel #1 and #2) at flow rates up to 10 gpm (38 lpm).  The Model 121A can be utilized as a fuel/water separator for fuel transfer applications in the following areas:

Marine – Filtration during fuel transfer from storage tanks to day tanks

Bus and Truck Terminals – Final fuel conditioning before fuel enters vehicle

Agriculture, Construction, and Mining – Filtration during fuel transfer from delivery truck to storage tank or from storage to tank to equipment

Airport Operations –  Cleans the fuel as the it is transferred into airport ground support equipment.

Railroad - Filtration during fuel transfer locomotive fuel storage tank

All other types of off-road machinery fuel transfer operations.   


  • Aluminum Construction: Aluminum is lightweight providing easy installation and a reduction in shipping costs.  The aluminum construction of the filter vessel is less susceptible to corrosion providing reliable and long term service.
  • Design:  The Model 121A's simplicity provides an easy installation and use filtration assembly for industrial purpose fuel/water separation and filtration applications.       
  • Engine Protection:  Protects today’s highly sophisticated fuel injection systems, thereby keeping diesel powered equipment in service.
  • Clean Fuel Delivery:  Prevents premature replacement of expensive components and revenue loss from equipment downtime resulting from contaminated fuel.



10" L x 10" W x 28" H (254 mm L x 254 mm W x 711 mm H)
25 lbs. (11.5 kg)
Inlet Connection
1.5 inch
Outlet Connection
1.5 inch
Coalescer Element
Separator Element
Materials Of Construction
Aluminum with Buna-N Seals 
Maximum Allowable Working Pressure
200 PSI
System Gauges & Indicators Inlet / Outlet Gauges (standard)
Water Accumulation Sight Glass (standard)
Differential Pressure Gauge (optional)
Construction Non-Code, but built by certified ASME Code welders
Performance Removes water from diesel fuel #1 and #2 to 130 ppm Total Water Content (0 ppm free, 10 ppm emulsified, 120 ppm dissolved)                              
NOTE: Total Water Content totals the individual categories of free water, emulsified water, and dissolved water.  (Total Water Content analysis per ASTM method D6304-16e1)
Applications Diesel Fuel #1 and #2
Finish Epoxy 
Available Options Floor Mounting
Wall Mount
Differential Pressure Gauge

Ordering Information

Product Number: 121A
Inlet/Outlet Connection Size and Type: 1-1/2" (NPT)

Spare Parts
• CI-3520P Coalescer Element
• 36W91 Separator Element
• 53M49 Buna-N Lid Gasket