Quick answer: Installing a filter press takes a level concrete foundation sized for the closed-press weight plus a full load of cake, clearance of at least 1 m on both sides and 1.5 m at the plate-shifting end, a cake drop of 1.2–2 m under the plate pack, a feed pump and pipework rated for the press’s filtration pressure, and a three-phase supply for the hydraulic unit and controls. Commissioning is a fixed sequence: level and bolt down, fit cloths, close the empty press and check the closing pressure, water-test the feed and filtrate lines, run one short cycle on dilute sludge, then bring the feed pressure up in stages over the first few cycles. Most start-up problems trace to three things: a foundation that is not level, a feed pump that reaches full pressure too fast, and cloths fitted with the neck off-centre.
Before the press arrives
Foundation and floor
A filter press concentrates its weight on the two end supports (the head stand and the tail stand) and, on larger presses, on intermediate legs under the side beams. The foundation must carry the shipping weight of the press plus the weight of the plate pack full of cake and water, with a margin for the dynamic load when the plates shift. For a 1500 mm press with 100 plates that is commonly 25–40 tonnes total. Cast a reinforced concrete slab, level to within 2 mm across the press length, with anchor bolts or drilled anchors to the drawing supplied with the order. A press installed on a floor that is out of level runs with the plate pack out of line, wears the side beams and hangers, and leaks on one side.
Clearances
| Location | Minimum clearance | Reason |
|---|---|---|
| Both sides of the plate pack | 1.0 m (1.5 m preferred) | Cloth changing, cake scraping, inspection |
| Plate-shifting end (tail) | 1.5 m plus the cylinder stroke | Access to the hydraulic cylinder and plate shifter |
| Head end | 1.0 m | Feed manifold, valves and gauges |
| Under the plate pack | 1.2–2.0 m | Cake drop into a hopper, bin, conveyor or trailer |
| Above the press | 0.5 m plus room for a hoist or crane where plates will be lifted out | Plate replacement |
Decide the cake handling before the foundation is cast. A press sitting on a mezzanine over a bay for a trailer or skip needs the mezzanine designed for the load; a press on the ground floor needs a pit or a conveyor. Cake handling is changed far more often than presses are, and a press set too low is the commonest layout regret. Our cake disposal article covers what the cake goes into.
Services
- Power: three-phase supply for the hydraulic power unit (typically 2.2–15 kW depending on press size), the feed pump, and any cloth wash pump, plus a control supply. Provide a lockable isolator within sight of the press.
- Feed line: pipe sized for the feed pump flow, rated for the press filtration pressure with margin, with an isolation valve, a pressure gauge at the press inlet and a relief valve set below the plate rating. Include a flushing connection.
- Filtrate: an open drain or a manifold to the filtrate return; for open-flow plates a drip tray and a collecting channel.
- Compressed air for membrane squeeze (6–8 bar, sized for the squeeze volume) or for cake air-blow, and for pneumatic valves.
- Wash water: for cloth washing, at the pressure the wash system needs, commonly 4–8 bar for manual hose washing and up to 80–100 bar for a high-pressure automatic washer.
- Water for the hydraulic system: none; the hydraulic unit is self-contained, but it needs an ambient temperature within the oil’s range and shade in hot climates.
Unloading and placing
Presses ship either assembled (small and medium sizes) or as head stand, tail stand, side beams, plate pack and hydraulic unit for site assembly. Lift only from the marked lifting points; never sling around the side beams, which bend, or lift by the plate pack. Set the head and tail stands on the anchor bolts, fit the side beams, and check level and alignment along and across the press before torquing the anchors. On an assembled press, check that transport bracing has been removed and that the plate pack rolls freely on the side beams. Our spare parts guide lists what should be on site before commissioning starts.
Commissioning sequence
- Mechanical checks. All anchors torqued; side beams parallel and level; plate pack complete and in the numbered order shown on the drawing, with membrane and chamber plates alternating correctly where both are used; plate hangers not bent; drip trays fitted.
- Hydraulic unit. Fill with the specified oil, bleed the cylinder, check rotation of the motor, and close the empty press slowly. Confirm the closing pressure on the gauge against the nameplate and that the pressure holds for 15 minutes with the pump stopped. A press that loses closing pressure has a valve or seal problem to fix before any sludge is fed.
- Cloths. Fit the cloths with the barrel neck centred in the feed port, the cloth hanging flat on both faces and the sealing face clean. Check the end plate cloths. Close the press again and confirm the closing pressure with cloths in place. See our cloth fixing guide.
- Water test. Feed clean water at low pressure, 1–2 bar, and walk the press: no leaks at the feed manifold, filtrate flowing from every outlet or corner, a light weep between plates at most. Raise to half the rated pressure and check again. This finds a torn cloth, an off-centre neck or a missing port O-ring before they are hidden by sludge.
- Feed pump and controls. Set the feed pump so pressure rises gradually: the first 5–10 minutes at 1–2 bar, then a ramp to the final filtration pressure over 20–40 minutes. On a variable-speed centrifugal pump this is a speed ramp; on a diaphragm pump, an air pressure ramp. Set the relief valve. Test every interlock: light curtain or safety bar on the plate shifter, emergency stop, low-oil-level and pressure switches. Our article on hydraulic system faults lists the checks.
- First sludge cycle. Run the first cycle on the thinnest sludge available, stop early, open the press and inspect the cake: even thickness across the plate, no wet centre, cake releasing from the cloth. Adjust polymer dose and feed ramp; see our polymer dosing guide.
- Bring up to full duty. Over the next three to five cycles, raise the feed end-pressure in stages to the design value, then add membrane squeeze and cake air-blow if fitted, one at a time, recording cycle time and cake solids at each step.
- Hand-over. Record the settings that gave the best cake, the closing pressure, relief settings, polymer dose and cycle timings on a commissioning sheet, and train operators on them.
The mistakes that cause most start-up problems
- Feed pressure applied too fast. The press blinds in its first weeks, cycles get longer, and the cloths are blamed. Ramp the pressure.
- Foundation not level. Plates hang out of line, one side leaks, and hangers wear. Shim before the anchors are torqued, not after.
- Cloth necks off-centre or port O-rings missing. Feed port leaks and torn cloths at the port. The water test catches this.
- Undersized cake handling. The press cannot be emptied fast enough and the cycle count per day falls. Plan the hopper and conveyor for the whole discharge of the press at once.
- Feed pump too small or too large. Too small never reaches pressure; too large hits full pressure in minutes and blinds cloth. Match the pump to the press curve. Our page on what pressure a filter press operates at explains the curve.
- No relief valve on the feed line. A blocked outlet or a stalled cycle over-pressures the plates. Fit one, set below the plate rating.
What Senjie supplies with the press
Every press ships with a foundation and clearance drawing, a wiring and piping schematic, the plate order diagram, the commissioning sheet above, and the operating and maintenance manual. Site installation supervision and commissioning by our engineers is available; for presses shipped to Southeast Asia, India and Africa we usually commission by video with the customer’s contractor on site, which covers the sequence above in one or two days. Automatic presses with plate shifters, cloth washers and PLC control take longer to commission; see our page on fully automatic filter presses.
Frequently asked questions
What foundation does a filter press need?
A level reinforced concrete slab, flat to within about 2 mm across the press length, designed for the press weight plus a full load of cake and water (commonly 25–40 tonnes for a 1500 mm press with 100 plates), with anchors to the foundation drawing supplied with the order.
How much space does a filter press need?
At least 1 m clear on both sides, 1.5 m plus the cylinder stroke at the plate-shifting end, 1 m at the head, and 1.2–2 m under the plate pack for cake discharge. Allow room above for lifting plates out.
What services does a filter press need?
Three-phase power for the hydraulic unit, feed pump and controls; a feed line rated for the filtration pressure with a relief valve and inlet gauge; a filtrate drain or return; compressed air if the press has membrane squeeze, air-blow or pneumatic valves; and wash water for cloth cleaning.
How long does commissioning take?
One to two days for a manual or semi-automatic press once the foundation, services and cake handling are ready; longer for fully automatic presses with plate shifters, cloth washers and PLC control. The first week of operation is used to bring feed pressure up in stages and set polymer dose.
Why does a new filter press blind its cloths so quickly?
Almost always because feed pressure is applied too fast. Ramp from 1–2 bar over the first 5–10 minutes to full pressure over 20–40 minutes; the slow start builds a porous cake that protects the cloth.
Can we install and commission the press ourselves?
Yes, with the drawings and commissioning sheet supplied; many customers do. Senjie can supervise on site or by video, and recommends at least video commissioning for the first cycles of membrane and automatic presses.
Send us your site layout and cake handling plan and we will check foundation, clearances and services before you cast concrete: request an installation review.