Pfeiffer Vacuum D-35614 Replacement for Asslar Series

Product Overview

Pfeiffer Vacuum D-35614 Replacement for Asslar Series: Seamless Transition & Compatible Upgrade

When your existing Pfeiffer Vacuum D-35614 oil-sealed rotary vane pump reaches end-of-life or becomes difficult to source, a smooth, validated replacement is critical to maintaining vacuum system uptime. The D-35614 is a single-stage, oil-sealed rotary vane pump widely deployed as a foreline or backing pump in turbomolecular pump systems, coating equipment, analytical instruments, and industrial process lines. TOPNLMS supplies verified D-35614 replacement units and compatible Asslar-series alternatives, fully tested and ready to integrate into your existing vacuum architecture with minimal modification.

The D-35614 operates at a nominal pumping speed of approximately 1.6 m³/h and achieves an ultimate pressure in the 10⁻¹ mbar range, making it a standard choice for backing Pfeiffer HiPace turbomolecular pumps such as the HiPace 10 and HiPace 80, as well as legacy TMH and TMU series turbopumps. When replacing the D-35614, engineers must verify the inlet flange standard (KF16 or KF25), the oil fill specification (Pfeiffer P3 oil or equivalent), the motor voltage rating (230V/50Hz or 115V/60Hz), and the exhaust port orientation to ensure the replacement unit fits within the existing cabinet or rack space without re-routing the foreline tubing.

Many facilities running older Pfeiffer Balzers DUO 1.5 M or DUO 2.5 M rotary vane pumps find the D-35614 a direct functional equivalent for backing duties, sharing the same KF16 inlet and compatible oil-mist separator fittings. If your system uses a Pfeiffer OB 1 oil mist filter or an ACP 15 dry scroll pump as a backing alternative, the D-35614 replacement integrates into the same foreline manifold without additional adapters. For systems that include a Pfeiffer RVC 300 or DCU 002 pump controller, the replacement unit’s motor wiring and thermal protection contacts are compatible with the existing controller interface, eliminating the need for control-panel rewiring.

In turbomolecular pump systems where the D-35614 backs a HiPace 300 or HiPace 700, the foreline pressure must remain below 5 mbar during operation. The replacement D-35614 unit supplied by TOPNLMS is run-tested to confirm it achieves the required base pressure before shipment, reducing commissioning risk on-site. For systems that also include a Pfeiffer PKR 251 or IKR 261 vacuum gauge, the replacement pump’s performance is validated against the gauge’s operating range to confirm system compatibility.

Physical installation of the D-35614 replacement follows the same footprint as the original: the pump mounts on standard anti-vibration feet, and the oil drain and fill ports are positioned identically, allowing technicians to complete an oil change and recommission the system within a standard maintenance window. If your facility also operates Pfeiffer HiScroll 6 or HiScroll 12 dry scroll pumps in adjacent process lines, the D-35614 replacement can serve as a wet-process backup or foreline unit without cross-contamination risk when proper oil-mist filtration is maintained.

For facilities managing a mixed fleet of Pfeiffer and Leybold vacuum equipment, the D-35614 replacement is compatible with standard KF (NW) fittings used across both brands, simplifying spare-parts inventory management. The unit ships with a full oil charge, inlet screen, and exhaust port cap, and is ready for immediate installation upon receipt.

Compatibility Comparison Table

Seamless Upgrade Solutions

A complete D-35614 replacement project typically involves more than just the pump itself. During the upgrade, facilities commonly address adjacent components to maximize system reliability and extend the maintenance interval. The Pfeiffer OB 1 oil mist separator should be inspected and replaced if the filter element is saturated, as a blocked exhaust filter will reduce pump performance and increase motor load on the new unit. The foreline tubing and KF16 centering rings and clamps should be replaced at the same time to eliminate leak paths that may have developed around the old pump’s inlet connection.

If the system uses a Pfeiffer RVC 300 pump controller, this is an ideal time to verify the controller’s thermal cutout settings match the replacement motor’s specifications. For systems where the D-35614 backs a HiPace turbomolecular pump, the HiPace’s venting valve and its associated Pfeiffer DCU 002 display and control unit should be checked for firmware compatibility with the current system configuration. Facilities that also maintain Pfeiffer PKR 251 full-range vacuum gauges in the foreline should recalibrate the gauge after pump replacement to establish a new baseline pressure reading for the upgraded system.

Where the original installation included a Pfeiffer ACP 15 dry scroll pump as a backing alternative, the D-35614 replacement can be installed in parallel as a wet-process or high-throughput backup, with a manual or solenoid-operated valve isolating the two backing paths. This dual-backing architecture is common in semiconductor and coating facilities where process continuity is critical and scheduled maintenance windows are short.

Retrofit Guidance FAQ

Q: Will the replacement D-35614 fit the existing foreline tubing without modification?
A: Yes. The replacement unit uses the same KF16 or KF25 inlet flange as the original. Confirm the flange size on your existing foreline before ordering, and specify it at checkout. No tubing modification is required.

Q: Is the motor wiring compatible with my existing Pfeiffer RVC 300 or DCU 002 controller?
A: Yes. The replacement motor uses the same terminal configuration and thermal protection contacts as the original D-35614, allowing direct reconnection to the existing controller without rewiring.

Q: What oil should I use, and is the replacement unit pre-filled?
A: The replacement unit ships pre-filled with a Pfeiffer P3-compatible oil. If your process requires a specific oil grade (e.g., for aggressive gas applications), please specify at the time of order and we will supply the unit dry with the appropriate oil included separately.

Q: Can the replacement pump achieve the foreline pressure required by my HiPace turbomolecular pump?
A: Yes. Each unit is run-tested to confirm it achieves ≤0.1 mbar ultimate pressure before shipment. For HiPace 300 or HiPace 700 applications requiring foreline pressure below 5 mbar during operation, the replacement unit is fully capable of meeting this requirement.

Q: How long does shipping take, and what is the lead time?
A: In-stock units ship from Xiamen within 1–3 business days. International delivery typically takes 5–10 business days depending on destination and customs clearance. Expedited shipping is available on request.

Q: What if the replacement unit does not perform as expected after installation?
A: All units are covered by a 12-month warranty from the date of shipment. If the unit fails to meet the specified performance parameters, TOPNLMS will arrange a replacement or full refund. Contact [email protected] with your order number and a description of the issue.

Warranty Assurance

Every Pfeiffer Vacuum D-35614 replacement unit supplied by TOPNLMS is covered by a 12-month warranty from the date of shipment. Prior to dispatch, each unit undergoes a pre-shipment run test to verify pumping speed, ultimate pressure, motor current draw, and oil-tightness. Units that do not meet specification are rejected and not shipped.

In the event of a warranty claim, TOPNLMS provides a replacement unit or full refund within the warranty period. Our after-sales response time is within 24 hours on business days. We maintain stock of D-35614 replacement units to support rapid turnaround for warranty replacements, minimizing your system downtime.

For procurement teams, we can provide a test report, packing list, and commercial invoice with each shipment to support customs clearance and internal asset management. Volume orders and blanket purchase agreements are available for facilities with recurring replacement requirements.