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Application Guide

Side Entry Mixers for Crude Oil Storage Tanks

Jensen side entry propeller mixers solve the most common crude oil storage problems — BS&W stratification, sediment build-up, and the need for costly manual tank cleaning. Self-supporting from the tank manway. No external supports required.

The Problem

Common Crude Oil Storage Tank Problems

Crude oil storage tanks present a unique set of mixing challenges. Without proper agitation, stratification, sediment accumulation, and surface crusting reduce tank efficiency, compromise product quality, and drive up maintenance costs.

BS&W Stratification

Basic sediment and water settles to the tank bottom, reducing effective storage capacity and contaminating product.

Gravity & Viscosity Variation

Crude oil stratifies by gravity and temperature, making accurate custody transfer sampling impossible without mixing.

Sediment & Sludge Build-Up

Heavy paraffin and sediment accumulate on the tank floor over time, requiring costly manual tank cleaning if not addressed.

Surface Crusting

In cooler climates or heated tanks, crude oil can form a crust at the surface — reducing capacity and creating safety hazards.

Solution 1

Crude Oil Tank Blending

The Jensen Series 400 and Series 600 fixed-angle side entry mixers are the standard solution for crude oil blending. A slight horizontal "swirl" combined with considerable vertical turnover maintains uniform gravity, viscosity, and temperature throughout the tank — ensuring accurate custody transfer sampling and reducing BS&W in delivered product.

Blending applications include prevention of stratification, elimination of surface crusting, heat transfer for uniform temperature, and blending of two miscible crude streams.

  • Uniform gravity and viscosity throughout the tank
  • Accurate custody transfer sampling at any level
  • Prevention of stratification in blended crude streams
  • Elimination of surface crusting and solidification
  • Uniform temperature distribution in heated tanks
  • Reduced BS&W in delivered product
Solution 2

Crude Oil Tank Cleaning — Vari-Angle Option

For tanks with significant sediment accumulation, the Jensen Vari-Angle option provides complete tank cleaning without manual mucking. The Vari-Angle feature allows the propeller flow stream to be directed to any area of the tank floor, re-suspending paraffin and heavy sediment that a fixed-angle mixer cannot reach.

The Vari-Angle feature is a precision, ball-type stuffing box allowing 60° angular movement. Over 15,000 Vari-Angle units are in service worldwide on crude oil and No. 6 fuel oil tanks. Mixer weight is supported entirely by two heavy-duty pin-type hinges — no turnbuckles, tie rods, or external supports required.

  • Complete removal of tank bottom sediment and sludge
  • Elimination of manual tank cleaning (mucking)
  • Reduced tank downtime and cleaning costs
  • Re-suspension of paraffin and heavy sediment
  • Increased effective storage capacity
  • Reduced BS&W in stored crude
Vari-Angle Mixer Details
Product Selection

Recommended Mixers for Crude Oil Storage

Series 400

Belt Driven — Fixed or Vari-Angle
1–15 HP
Vari-Angle Available

Blending and tank cleaning on small to medium crude oil storage tanks.

Series 400 Details

Series 600

Gear Driven — Fixed or Vari-Angle
5–75 HP
Vari-Angle Available

Blending and tank cleaning on medium to large crude oil storage tanks. Preferred for pipeline terminal service.

Series 600 Details

Series 800/900

Belt or Gear Driven
15–200 HP

Heavy-duty service on large crude oil storage tanks. Petro-Block safety system standard.

Series 800/900 Details
Installation Advantage

No External Supports Required

Jensen side entry mixers are designed to be self-supporting from the tank manway or nozzle flange. The Series 400 IOM manual states explicitly: "No additional supports are necessary." The same applies to the Series 600, 800, and 900.

The short shaft and low-overhang design allow the nozzle/manway flange to carry the full mixer load. You will never need tie rods, turnbuckles, slings, floor supports, or external structural braces.

Note: The tank manway or nozzle must be structurally adequate to carry the mixer weight, motor weight, and operating loads. For thin-wall tanks or field-added nozzles, the tank fabricator should verify that the nozzle and surrounding shell reinforcement are adequate.