851E-3 Fuel/Water Separator

The Model 851E Series are diesel fuel/water separation and filtration filter vessels that employ Kaydon Filtration coalescing technology to separate water from diesel fuel.  In addition to water removal, the coalescer provides a particulate filtration layer to remove harmful particulates along with providing protection for the coalescing stage.  The 851E vessels are designed from rugged, heavy-duty, carbon steel and built per ASME Code.  The Model 851E Series are designed to provide filtration and water removal for Diesel # 1 and # 2.   

The Model 851E Series can be used as an in-line fuel purifier in 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 – Provides clean fuel as the fuel 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  


  • ASME Code Construction: Using the ASME Code design criteria, the Model 851E Series are built for reliable and long term use in any industrial fueling environment. 
  • 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.

           Maximum Flow Rates
                   851E Series


Diesel Fuel # 2 – Maximum Flow Rate


20 gpm


60 gpm


100 gpm


200 gpm


320 gpm


Diesel Fuel #1 and #2




17"L x 24"W x 42"H (435 mm L x 610 mm W x 1065 mm H)
210 lbs (95 kg)
Inlet Connection
2 inch NPT (standard) / 2 inch 150# RF Flange (optional)
Outlet Connection
2 inch NPT (standard) / 2 inch 150# RF Flange (optional)
Coalescer/Separator Element
Coalescer Element Model Number: CI-3520P (qty. = 3)
Separator Element Model Number: 36W91 (qty. = 3)
Materials of Construction
Carbon Steel with Viton O-Ring Lid Seal
Maximum Allowable Working Pressure
150 psig @ 250 F
Gauges & Indicators
Inlet-Outlet Gauges (standard)
Water Level Sight Glass Indicator (standard)
Differential Pressure Gauge (optional) 
Design and Construction ASME Code Section VIII, Division 1, latest edition (includes "UM" Stamp)
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
Coatings Interior:  Epoxy
Exterior: Epoxy, Color: Kaydon Blue
Available Options
  • Automatic Air Release
  • Mechanical Automatic Water Drain Assembly (add 30 lbs. to weight and 4 inches to length)
  • Differential Pressure Indicator (0-35 psid / 0-2.5 kg/cm2))
  • Pressure Relief Valve (set point = 150 psig / 10.5 kg/cm2)
  • 150# RF Flange Connections
  • ASME Code "U" Stamp 

Example Ordering Code
Part Number 851E-3D-MA-AP-NPT-DPG-E
851E = Series Number
3 = Accepts three coalescer elements / accepts three separator elements (6 elements total)
D = Designed for Diesel Fuel #1 and #2 Service
MA = Mechanical Automatic Water Drain Assembly
A = Automatic Air Release Valve
P = Pressure Relief Valve
NPT = Inlet/Outlet Connection Type: NPT / Size = 2 inch
DPG = Differential Pressure Gauge
E = One Set of coalescer element and separator elements included and pre-installed.

Consumable Spare Parts
• CI-3520P (qty. = 3)
• 36W91 (qty. = 3)
• Vessel Lid Seal A900322 (qty. = 1)