Skip Navigation LinksEvoqua Water Technologies > en > Brands > JWI > Small Capacity J-Press Sidebar Filter Presses

 contact product expert

Mike Jager
Product Manager

Small Capacity J-Press Sidebar Filter Presses

Designed to optimize performance and minimize labor

Designed to optimize performance and minimize labor, the Small Capacity J-Press Filter Press features modularized air-hydraulic, self compensating closure systems, choice of filter plates and cake thicknesses for versatile performance, manual or semi-automatic plate shifting to minimize labor requirements and an optional pump control system to provide process automation. This filter press combines rugged ASTM-A36 steel construction, precision engineering, ease of operation and a wide range of features and options to tackle the most difficult dewatering problems.

Our newest J-Press model, designed for the low- to medium-sized throughput flowrates is the 630 MM system manual press. It comes with ergonomic features which make this filter press very easy to use and maintain. This design also reduces the number of pinchpoints, adding safety to the list of benefits. Check out the J-Press 630 MM page here.

Download the J-Press 630 MM brochure here:



 The Industry Standard Liquid/Solid Separation Process

The Small Capacity J-Press Filter Press is the cost-effective solution for producing high solids filter cake with extremely high clarity in the liquid effluent. Considered by industry professionals as the premier sidebar filter press, the J-Press filter press combines rugged construction, precision engineering, ease of operation and a wide range of features and options to tackle the most difficult dewatering problems. The J-Press filter press is one of the most versatile dewatering devices on the market, being used in a wide variety of industrial and municipal applications. The J-Press filter press can be used to recover both solids and liquids from a waste or process stream. With superior materials of construction, the J-Press filter press is especially useful in the dewatering of aggressive acid and alkali suspensions.

Available in a wide range of sizes and styles, the Small Capacity J-Press Filter Press can be configured to provide a dewatering solution to most all process flows from as little as 25 gallons to 1,000,000 gallons per day. It produces consistent results under varying influent conditions.    



How It Works

The cycle begins when solids-laden sludge or slurry is pumped under pressure into the press chambers through the piping at the stationary head of the filter press, via the feed connection. As each cake chamber fills with sludge, the liquid passes through the cloth medium, across the drain-field, through the drain ports and exits via gravity out of the corner discharge eyes. Because the J-Press is a batch filtration system, the press capacity can be adjusted by adding or removing filter plates. A back-up plate can be inserted to sections off the portion of the filter plate pack not in use.



Filtration Medium

The prime function of the media in cake filtration is to provide a porous support structure for the filter cake as it develops and builds. Initially, some solids may pass through the cloth media causing a slight turbidity in the filtrate, but gradually the larger particles within the slurry begin to bridge the openings in the media reducing the effective opening size. This allows smaller particles to bridge these reduced openings initiating the cake filtration process. Once a layer of solid particles achieves 1 to 2 mm in thickness, this precoat layer serves to separate out finer and finer particles as the cake builds in thickness, yielding a filtrate that is very low in turbidity.

 Uniform, Consistent Cake Solids

The Small Capacity J-Press Filter Press is simple to operate. A single switch activates the pneumatic or electrically actuated hydraulic system. The plate stack forms a series of chambers, each covered with a filter cloth. With the plate stack clamped tightly in place, a solids-laden slurry is pumped, under pressure, into the plate chambers through a central feed connection.

The plate chambers fill uniformly with solids while the pump pressure and flow keep the solids deposited on the vertical surfaces of the plate chambers. Liquid passes through the filter cloths as clean filtrate flows to the end of the press where it is collected at a common manifold.

The solids continue to fill the plate chambers and are compacted in the press by the feed pump until the chambers are completely full. The feed cycle is discontinued and an air blow down is initiated for 5-15 minutes to remove any freestanding water within the cake and the press. The hydraulic closure of the press is then retracted, the individual filter elements are separated and the solids are discharged as "dry" filter cake to an appropriate receptacle or conveyance system.

Superior Filter Plate Technology

Adding to the versatility of the J-Press® filter press is the large selection of filter plates available from Evoqua. Based upon the process operating demands, filter plates are selected for each specific application. Filter plates are available in corrosion resistant polypropylene, PVDF and nylon. Plates can be configured as gasketed or non-gasketed, diaphragm (membrane) squeeze, or plate and frame designs. Like the J-Press filter press itself, the filter plates can be designed to withstand operating pressures up to 225 psi (16 bar).

Cake Wash or Air Blowdown

The inherent flexibility of the J-Press filter press makes it ideal for recovering solids, liquids or both. In processes where the filter cake may need treatment prior to discharge, the J-Press cake wash/air blowdown manifold can be used to force wash liquid through the cake. The manifold consists of piping and valves connecting the four corner filtrate ports into a common discharge pipe. By closing the appropriate valves, a wash liquid is pumped through the filter cake, and discharged out the diagonally opposed port. This can be followed by a compressed air blowdown, further removing moisture from the cake and filter plate drainage channels.


 Features, Benefits and Options

Features and Benefits

The J-Press filter press was the first to feature, in a single design:

  • a self-compensating air/hydraulic closure system for ease of maintenance,
  • gasketed filter plates for virtually leak free dewatering,
  • semi-automatic plate shifting for labor savings and safety,
  • automatic pump controls and
  • a superior paint system that provided the highest level of protection from corrosion.


The J-Press filter press quickly set the benchmark for filter press performance. Today, the J-Press filter press offers the most advanced automation available, from fully automatic plate shifting and cloth washing to PLC controls and a full complement of ancillary slurry processing and cake handling systems.

Adaptability to applications, processes and capacities are the underlying values of J-Press® filter press. Features include:

  • Full range of capacities: 250 mm to 1000mm
  • Low and high pressure: 100 psi (7 bar), 225 psi (16 bar), higher pressure available — consult factory
  • Standard plate packs: Non-Gasketed Plates, Gasketed Plates, Diaphragm Squeeze Plates, Plate and Frame Stainless Steel Sidebar Covers
  • Closure Systems: Manual, Automatic Closure (Air/ Hydraulic), Automatic Closure (Electric/Hydraulic)
  • Control Systems: Standard Control Panel, Automatic Pump Control System, PLC
  • Control Standard Manifolds: Air Blow Down Manifold, Double End Feed Manifold, Core Blow Down Manifold, Cake Wash Manifold, Precoat Manifold (other configurations available — consult factory)
  • Expansion options available for future capacity Plate Shifting: Air Operated Semi-Auto Plate Shifter, Automatic Pry Shifter, Automatic Pry Shifter and Bump, Automatic Pry Shifter, Bump and Weigh (ACDDS), Multi-Plate Pull
  • Automatic Cloth Washing
  • Material handling: Filter Cake Dumpster, Extended Legs and Chute, Platform, Drum Disposal System, Platform, Roll-off Container System Cake Conveyors
  • Drip Trays: Manual, Automatic Spread Leg Design Safety: Splash Curtain, Safety Guard, Safety Light Curtains, Deadman Control Button, Safety Tripwire, Hyd. Clamp Pressure/Feed Pump, Interlock, Hyd. Control System/Press, Pressure Interlock, Hyd. Clamp Pressure/Squeeze, System Interlock
  • Custom Paint Systems: Nicklad® Coating


Automation Options Available

The Small Capacity J-Press® Sidebar Filter Press can be fully automated to produce high solids filter cake with extremely high clarity in the liquid effluent. Considered by industry professionals as the premier filter press, the J-Press filter press combines rugged construction, precision engineering, ease of operation and a wide range of features and options to tackle the most difficult dewatering problems. These automated J-Press filter presses are key systems in municipal and industrial facilities around the world.

Spec Charts and Dimensions

Diagram Notes

Based on 32 mm cake thickness, 100 psi (7 bar)


Dewatering@evoqua.com Small Capacity J-Press Sidebar Filter Presses