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OTL™ Once Through Lubricated Vacuum Pumps

India's original rotary vane vacuum pump with Once Through Lubrication. Achieves and maintains consistent deep vacuum throughout the process, with no drop, while handling corrosive, solvent, and aggressive vapors.

Vacuum to 1 mmHg (abs) No vacuum drop Handles corrosive vapors Made in India

OTL™ for handling corrosive/acidic applications

Every design decision in the OTL™ series traces back to three physical facts about vapor and corrosion that conventional pump designers ignored.

1

Vapors in vapor state can't corrode

Whenever any material is in vapor stage, its corrosive properties are drastically reduced. OTL™ maintains an operating temperature of 50-70°C so that vapors sucked in remain in vapor form throughout their stay in the pump, and are exhausted without ever condensing.

2

Condensation causes all corrosion

Whenever condensation of vapors occurs inside a vacuum pump, maximum corrosion of components takes place. OTL™'s first stage is positioned on top of the second stage so any condensate drains by gravity when stationary, and is continuously expelled during operation.

3

Contaminated oil must never recirculate

Corrosive vapors contaminate lubricating oil badly. In conventional pumps, this contaminated oil keeps recirculating, degrading both vacuum performance and pump internals. In OTL™, fresh oil is continuously injected and expelled, never recirculated.

Built for long, trouble-free service

Two-Stage Design

Top stage (connected to plant) sits above bottom stage (exhaust stage). This gravity-drain layout prevents condensate accumulation and the corrosion it causes.

4-Plunger Oil System

Four independent plunger pumps continuously inject fresh oil from a 23-litre tank (220-330 ml/hr depending on model) for lubrication and sealing. Contaminated oil exits via the exhaust.

Radiator Cooling

A 100-litre water tank with a 1 HP radiator fan maintains 50-70°C operating temperature. Water never contacts process vapors. Coolant can be added to reduce topping-up frequency.

Phenolic Fiber Vanes

Heat-treated toughened phenolic fiber vanes withstand aggressive solvents, methanol, EDC, MDC, toluene, xylene, benzene, hexane, with minimal stator wear. Replaceable without disturbing motors or pipelines.

Viton Oil Seals + Metal Shaft Seal

Viton oil seals for long life, which are compatible with most vapors. Bearings are filled with high melting point grease.

Cast Iron Body

Stator, rotor, and end covers are cast iron. With proper operating procedure (warm-up and air bleeding after each batch), cast iron components deliver long service life even with corrosive vapors, with economical and minimal maintenance.

OTL™ Models

Four standard models for plant/large-scale applications. All models share the same OTL™ technology and are fully serviced from Thane, Maharashtra.

Single Stage

OTL™ 105

Entry-level industrial

Stages Single
Oil consumption 220 ml/hr
Ultimate vacuum ≤ 1 mmHg
Power requirement 7.5 HP
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Most Popular
Single Stage

OTL™ 175

Mid-range industrial

Stages Single
Oil consumption 220 ml/hr
Ultimate vacuum ≤ 1 mmHg
Power requirement 11.5 HP
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Double Stage

OTL™ 250

High-capacity industrial

Stages Double
Oil consumption 330 ml/hr
Ultimate vacuum ≤ 1 mmHg
Power requirement 19 HP
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Heavy Duty

OTL™ 800 2S

Large-scale industrial

Stages Double (2S)
Oil consumption Contact us
Ultimate vacuum ≤ 1 mmHg
Power requirement 16.5 HP
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All OTL™ models share these specifications:

Operating temp: 50-70°C
Oil grade: 20W40
Vane material: Phenolic fiber
Seals: Viton oil seals
Body: Cast iron (stator, rotor)
Oil tank: 23 litres
Cooling water: ~100 litres
Spares: Ship from Thane

What OTL™ pumps are designed for

Ideal for high vacuum applications in the 5-0.1 torr range where consistent vacuum and vapor handling are non-negotiable.

API Distillation & Purification

OTL™'s zero oil-contamination design is critical for API quality. No recirculated oil means no risk of cross-contamination into your active pharmaceutical ingredient. 3,000+ pharma installations across India.

Vacuum Drying

Consistent vacuum throughout the drying cycle means lower operating temperatures, reduced batch times, and no product degradation. OTL™ maintains vacuum even under high solvent vapor loads at the start of a batch.

Solvent Recovery

OTL™ handles methanol, EDC, MDC, toluene, xylene, benzene, hexane vapors without condensation in the internals. Solvent flushing procedure available for powder trace removal.

Granulation & Coating

Used as vacuum source for fluid bed dryers and coating pans. Reliable vacuum maintenance ensures consistent granule quality batch after batch.

Vacuum Distillation

Ideal for high vacuum distillation in the 5-0.1 torr range. Lower boiling points under vacuum reduce thermal degradation of heat-sensitive products. OTL™ maintains these pressures consistently, without the boiler a steam ejector would require.

Chemical Synthesis

Many synthesis reactions require controlled vacuum to manage reaction equilibria and remove volatile by-products. OTL™'s stable vacuum eliminates the vacuum drop that derails sensitive reactions.

Flavours & Fragrances

Extraction and concentration of natural compounds at low temperatures. OTL™'s clean, oil-free process stream protects product integrity, no oil migration into your flavour compounds.

Steam Ejector Replacement

OTL™ was specifically designed as a low-cost replacement for steam jet ejector systems. Remove your boiler dependency entirely, most customers recover the investment within 12-24 months from energy savings alone.

Acidic & Corrosive Vapor Handling

Conventional SS 316 pumps fail in corrosive vapor service, not because they corrode, but because the friction between working parts causes seizure. OTL™'s cast iron construction with proper operating procedure (warm-up + air bleeding after each batch) outperforms expensive SS alternatives.

The key is operating temperature: at 50-70°C, corrosive vapors remain in vapor form throughout their transit through the pump and exit without ever condensing onto metal surfaces.

Vapors handled

Methanol, EDC, MDC, toluene, xylene, benzene, hexane, acidic vapors, water vapor, aggressive solvents

Required operating procedure

15-minute warm-up before connecting to plant. 3-minute air bleed after each batch. Solvent flush if powder traces are present.

Simple SOPs. Easy to follow.

OTL™ pumps were designed so that vanes and bearings can be replaced in a short time without disturbing motors, process pipelines, or electricals. Your maintenance crew will find routine jobs straightforward.

Daily
  • Check oil level and top up if necessary
  • Check water level and top up if necessary
  • Air bleed after every batch (3 minutes)
Weekly
  • Clean oil plunger pipes; verify oil flow
  • OTL™ 105/175: 2 drops/stroke per stage plunger
  • OTL™ 250: 3 drops top stage, 2 drops bottom
Every 2 Weeks
  • Check individual stage vacuums
  • !Below 600 mmHg: replace vanes within 10 days
  • !Below 575 mmHg: replace vanes immediately
Every 2 Months
  • Drain + clean oil tank; refill fresh oil (~30 min)
  • Service all 4 oil plungers (~30 min)
  • Drain water, fill fresh DM water (or every 3-4 months with coolant)

OTL™ vs. conventional vacuum sources

Criterion OTL™ Pump Dry Screw Pump Oil Sealed Pump Steam Ejector
Ultimate vacuum ≤ 1 mmHg 0.1 torr Degrades over time Narrow range only
Oil contamination None None High risk None
Boiler required No No No Yes, major cost
Energy cost Low Low Moderate Very high
Corrosive vapors Handled Handled Causes seizure Limited
Effluent / pollution Minimal Minimal Oil mist exhaust Creates effluent
Spares availability Same day (Thane) Long wait time Regular Varies
Cost of purchase Economical Extremely expensive Affordable Expensive
Cost of maintenance Economical Extremely expensive Economical Expensive

Tell us your vacuum requirement.
We'll recommend the right model.

Bring your target vacuum level (torr or mbar), process type, and vapor load estimate. Our engineers will size the correct OTL™ model and walk you through the installation requirements.

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