How to Use a Hydraulic Oil Press Machine (Step-by-Step Guide)

Hydraulic oil press machines are widely used for extracting oil from seeds and nuts such as sesame, peanut, soybean, rapeseed, sunflower seed, almond, and walnut. Compared with screw presses, hydraulic oil presses work in batch mode and use high hydraulic pressure to obtain high-quality oil with better flavor and higher nutritional value.

This guide explains the real industrial operating process based on actual factory experience.

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Step 1: Prepare Raw Materials

Before pressing, raw materials must be properly prepared:

1. Cleaning

Remove stones, dust, metal, and impurities to avoid damaging the press chamber.

2. Drying or Roasting

Depending on oil type:

Oil Type	Process
Sesame	Light roasting
Peanut	Roasting
Soybean	Usually hot pressing
Rapeseed	Hot pressing
Almond / Walnut	Cold pressing

Hot pressing improves oil yield.

Cold pressing keeps more nutrients and aroma.

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Step 2: Choose the Right Press Barrel

Hydraulic presses usually use two standard barrel sizes:

Standard Barrel

• Inner diameter: 390 mm
• Height: 800 mm
• Theoretical capacity: 100 kg per batch
• Real working capacity: 60 kg per batch (most customers)

100 kg is the extreme limit and requires pre-compression.

Small Barrel (for Sesame)

• Inner diameter: 300 mm
• Capacity: 30 kg per batch
• No pre-compression required

This 30 kg barrel is especially popular for sesame oil and small oil mills.

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Step 3: Pre-Compression (Important for Large Batches)

Pre-compression is used when loading close to maximum capacity.

Purpose:

• Compress raw materials
• Reduce air gaps
• Allow more material into the barrel

Without pre-compression, 100 kg loading is almost impossible.

In real production:

Most customers load about 60 kg and start pressing directly.

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Step 4: Set the Working Pressure

All hydraulic oil presses have similar pressure design:

Parameter	Value
Rated pressure	60 MPa
Recommended low pressure	55 MPa
Recommended high pressure	60 MPa

Operating below 60 MPa:

• More stable
• Less wear on seals
• Longer hydraulic system lifespan

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Step 5: Start Pressing

Once pressure is applied, oil will flow out naturally from the barrel.

Typical pressing time:

Mode	Time
Hot pressing	30–40 minutes
Cold pressing	About 2 hours

Cold pressing takes longer because:

• Lower temperature
• Lower oil fluidity
• Higher viscosity

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Step 6: Oil Filtration

Fresh oil contains:

• Fine cake particles
• Impurities

Use:

• Plate filter
• Vacuum oil filter

After filtration, oil becomes:

• Clear
• Bright
• Ready for filling

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Step 7: Cake Discharge

After pressing:

• Release pressure
• Open barrel
• Remove oil cake

Oil cake can be used for:

• Animal feed
• Fertilizer
• Further extraction

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Typical Production Capacity

For a standard hydraulic press:

Barrel	Per Batch	Time	Hourly Output
Small barrel	30 kg	30–40 min	~45–60 kg/h
Standard barrel	60 kg	30–40 min	~90–120 kg/h
Max limit	100 kg	With pre-compression	~150 kg/h

(Cold pressing output is about 50–60% of hot pressing)

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When Is Hydraulic Oil Press the Best Choice?

Hydraulic presses are ideal for:

• High-value oils
• Small oil mills
• Organic / cold pressed oil brands
• Lab and R&D oil extraction
• Boutique edible oil production

Not ideal for:

• Large industrial continuous production
• Very low-cost commodity oil

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Summary

Hydraulic oil press machines are designed for quality-first oil production, not mass quantity.

Key practical points from real operation:

• 100 kg is theoretical maximum, 60 kg is real working capacity
• Sesame uses 30 kg barrel
• Working pressure: 55–60 MPa
• Hot press: 30–40 min
• Cold press: ~2 hours

This is why hydraulic presses are widely used in premium edible oil factories worldwide.

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