Edwards Scroll Pumps

Edwards scroll pumps are some of the most widely used oil-free vacuum pumps in laboratories and analytical instruments. They deliver clean, quiet vacuum without oil changes, exhaust mist or the risk of oil back-streaming into your system. At Provac Sales, we supply Edwards nXDS and XDS scroll pumps and help customers choose the right model, configuration and accessories.

Edwards Scroll Pump Models We Carry

Our Edwards scroll pump collection includes:

• Edwards nXDS6i, nXDS6iC and nXDS6iR
• Edwards nXDS10i
• Edwards nXDS15i
• Edwards nXDS20i

Some nXDS models are also listed in C and R configurations. Check the product page for the exact version available.

• Edwards XDS5 and XDS10
• Edwards XDS35i and XDS46i
• Edwards XDS100B

The number in the model name reflects the nominal pumping capacity in cubic metres per hour. An nXDS10i, for example, is rated at about 7.5 CFM with an ultimate pressure of about 5 x 10-3 Torr, while the nXDS6i is rated at about 4 CFM. The XDS35i, XDS46i and XDS100B cover larger systems that need more speed.

What the C and R Suffixes Mean

Edwards offers several nXDS models in more than one version:

• Standard i versions are for general clean applications
• C versions are chemically resistant, with materials and features designed for corrosive or aggressive vapors
• R versions are a variant intended for specialized applications; confirm the specification on the Edwards datasheet for your model

Choose the version that matches the gases you are pumping. If you are unsure, send us your application and we will recommend the right configuration.

How a Scroll Pump Works

A scroll pump uses two interleaved spiral scrolls. One is fixed and the other orbits around it without rotating. As the orbiting scroll moves, it traps pockets of gas at the outer edge and moves them toward the center, compressing them until they are discharged at the exhaust. A tip seal on each scroll keeps the pockets sealed.

Because the scrolls do not touch and there is no oil in the pumping chamber, the pump is clean and quiet. The tip seals are the main wear item and are replaced during routine service.

How to Choose an Edwards Scroll Pump

Consider the following before selecting a model:

• Required pumping speed and the volume of your chamber or instrument
• Ultimate pressure needed, especially if backing a turbo pump
• Gases being pumped, including solvents, corrosives or rare gases
• Noise limits in the lab, since nXDS pumps are designed for quiet operation
• Inlet and exhaust connections, typically KF16 or KF25
• Electrical supply, with nXDS models accepting single-phase 100-240V at 50/60Hz
• Whether you need speed control, remote operation or serial communication

Applications for Edwards Scroll Pumps

Edwards scroll pumps are used for:

• Backing turbo pumps in pumping stations and instruments
• Mass spectrometers, electron microscopes and surface analysis systems
• Rotary evaporation, freeze drying and vacuum ovens
• Glove boxes and load locks
• Leak detectors and vacuum test equipment
• Physics and materials research
• Any lab where oil contamination or noise is a concern

Scroll Pumps vs Rotary Vane Pumps

An Edwards RV or E2M rotary vane pump reaches a lower ultimate pressure and costs less to buy, but it needs regular oil changes and exhaust filtration and can contaminate clean systems. An Edwards scroll pump costs more upfront but removes oil from the equation, which is why many labs switch to scroll pumps when they replace older vane pumps.

For lighter tasks that do not need such a low pressure, an Edwards diaphragm pump can be a smaller, lower-cost oil-free option.

Maintenance and Tip Seal Replacement

Scroll pumps need little maintenance, but tip seals and bearings eventually wear. Signs that service is due include:

• Higher ultimate pressure than normal
• Slower pump-down times
• Increased noise or vibration
• Dust from worn tip seals at the exhaust

Tip seal replacement is a routine service. Pumping solvents without a cold trap, or running the pump at high inlet pressure for long periods, can shorten tip seal life. Running the pump with the gas ballast open for a few minutes after solvent use helps clear vapors.

New vs Rebuilt Edwards Scroll Pumps

New nXDS pumps suit new installations and users who want the latest models and features. Rebuilt units can be a cost-effective option for replacing a pump in an existing instrument or station. Each listing and quotation confirms the condition and warranty coverage.

Edwards Scroll Pump Repair

Our published repair capabilities include Edwards ESDP and GVSP series scroll pumps. For nXDS and XDS pumps, contact us with the model and serial number so we can review service options before you ship. Submit an RMA request and complete the contamination data sheet, especially if the pump has handled solvents or hazardous gases. Learn more on our pump repair page.

Frequently Asked Questions

What is the difference between nXDS and XDS?

The nXDS series is the newer generation, with an inverter drive, wide voltage range, quieter operation and longer service intervals. XDS pumps are an earlier generation still installed widely in instruments and labs.

Can an Edwards nXDS pump back a turbo pump?

Yes. nXDS pumps are commonly used to back turbo pumps in compact high vacuum systems. Check the turbo pump's backing requirements to confirm the right size.

How often do nXDS tip seals need replacing?

It depends on the application and run hours. Clean applications can run for long periods between services, while solvent or dusty applications need more frequent attention.

Is the nXDS suitable for corrosive gases?

Choose the C version for corrosive or chemically aggressive applications. Standard i versions are intended for clean duty.

Getting the Most From an Edwards Scroll Pump

Simple installation and operating choices can extend the life of an nXDS or XDS pump considerably:

• Keep the inlet line as short and wide as practical to preserve pumping speed at the chamber
• Use a cold trap or condenser when pumping solvent vapors, so liquid does not reach the scrolls
• Avoid running the pump for long periods at high inlet pressure, which loads the tip seals and raises operating temperature
• Leave space around the pump for cooling air, and keep the cooling fan inlet free of dust
• Use the gas ballast or purge feature as recommended when pumping water vapor or condensable gases
• Fit an inlet filter in dusty applications to protect the scrolls from particles

Recording the ultimate pressure when the pump is new or freshly serviced gives you a useful benchmark. When that figure starts to rise, it is usually time to plan a tip seal service rather than waiting for a failure in the middle of an experiment.

Request a Quote on Edwards Scroll Pumps

Send us the model and version you need, or describe your application, target pressure and gases. We will confirm availability and recommend the right Edwards scroll pump. Contact us or call 831-462-8900.