Edwards Diffusion Pumps: Diffstak Model 63/150 (Unvalved)

Integrated, compact design - minimum size with maximum pumping capacity
Low backstreaming - the shape of the pump body, combined with the inlet baffle, reduces backstreaming to a minimum
Lowest number of seals to complete pump installation - this means clean pumping, with minimal outgassing
Unvalved ISO flange
Pumping speed 135 l/sec

Diffstak concept

The standard Diffstak consists of a water-cooled diffusion pump, an inlet baffle, a high vacuum valve and roughing line connections all integrated in a single, vacuum brazed, stainless steel casing.

The integrated design of the Diffstak results (when compared with conventional diffusion pumps) in a reduction in the number of elastomer seals required to complete the installation. The neat and compact Diffstak therefore offers exceptionally clean pumping with virtually no outgassing.

The Diffstak pump has a one-piece jet assembly which is easy to remove, clean and replace. The Diffstak is a fully fractionating pump. The ejector stage ensures high backing pressure performance and continuous fluid purification.

The standard Diffstak contains no high vacuum valve. The unvalved Diffstak is best for applications where the highest ultimate vacuum is required, or where a high vacuum valve is not needed. Other models available on special request.

Diffstak features

The Diffstak pump has a gauging port in the integral roughing line to allow you to fit a Pirani gauge head to monitor the system pressure.

A mounting plate is fitted to the ejector stage to accommodate an optional thermal snap-switch.

The heater in the Diffstak is a flat plate which is easy to replace and which means that the electrical terminal box on the base of the pump can be rotated to suit your application.

The conveniently located dipstick and drain assembly allows you to check the fluid level, to drain the fluid and to pour more fluid into the pump while the pumps remain connected to your vacuum system.

Edwards Diffusion Pumps

Scientific Instrument Services can supply the full range of Edwards Diffusion Pumps. This includes the Diffstak series including the models 63/150, 100/300, 160/760 and 250/2000 as well as the many other models available.

There are three types of Diffstak available: the standard Diffstak, the cryo-cooled Diffstak and the unvalved Diffstak.

The standard Diffstak is the basic model, available in four sizes, with a water-cooled inlet baffle. The high vacuum valve is part of the inlet flange and can be either manually or pneumatically operated. The standard pump offers clean and fast pumping without the need for liquid nitrogen.

The cryo-cooled Diffstak has a liquid nitrogen cooled inlet baffle with an integrated liquid nitrogen reservoir. The cryo-cooled Diffstak is ideal for applications where very high vapour loads are pumped. Like standard Diffstak, the cryo-cooled Diffstak is available in four sizes with either manually or pneumatically operated high vacuum valve.

If you are replacing a diffusion pump on your mass spectrometer and have the model number or pump specifications, give us a call and we can supply a replacement.

Technical Data
Pumping speed (nitrogen)	135 e/s
(hydrogen)	200 e/s
Minimum backing pump displacement for maximum throughout	3 cfm
Recommended backing pump	RV-5
Recommended fluid	Santovac
Fluid charge (dry)	60 ml
Inlet connection compatible with	ISO63
Backing connection	NW10
Cooling water connection	6 mm (0.234") compression couplings
Heater power	0.45 kW
Minimum cooling-water flow at 68�F	42 Ih^-1
Weight	17.6/20 lb

Part No.	Description	est wt.	Quantity In Stock	Price	Quantity to order
Model 63/150 Diffstak, UOM=EA
B34433976	unvalved (110-125 volts)	20	0^(#)	$3132.00	1
B34433977	unvalved (210-225 volts)	20	0^(#)	---	---
B34433978	unvalved (230-250 volts)	20	0^(#)	$4500.00	1
(#) Standard lead-time for out-of-stock items is approximately two weeks.
Ordering information. International (non-US) prices available through your local dealer.

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