Generic selectors
Exact matches only
Search in title
Search in content
Post Type Selectors

Back Pull-Out Pumps

Maintenance & Reliability
Heinz Bloch

Back Pull-Out Pumps

Many process pumps are designed and constructed to facilitate field repair.  On the so-called back pull-out pumps (see illustration, also Ref. 1), shop maintenance can be performed while the casing and its associated suction and discharge piping are left undisturbed.

The impeller, pump shaft and bearings remain with the power end which is simply lifted up and removed for refurbishment, if needed. A spacer coupling is used; disc-pack couplings are much preferred over certain cheap and therefore popular elastomer-in-torsion couplings.

Although costing more initially, well-designed disc-pack couplings save money in the long run. In to get a long run, failure avoidance and safety are the ever-present key goals of reliability-focused users (Ref. 2).

Because this is the fundamental definition of reliability, it, like truth, will never change. Reliability will touch on a number of issues with process pumps; these issues and their solutions will be explained in many future postings. In particular, Ref. 3 will both highlight and summarize much of this in a 724-page book.


  1. Bloch, Heinz P. and Allan Budris; “Pump User’s Handbook: Life Extension,” 4th Edition, (2014), Fairmont Publishing, Lilburn, GA, ISBN 0-88173-720-8
  2. Bloch, Heinz P.; “Pump Wisdom: Problem Solving for Operators and Specialists”; (2011), Wiley & Sons, Hoboken, NJ; ISBN 9-781118-04123-9
  3. Bloch, Heinz P.; “Petrochemical Machinery Insights,” (2016) Elsevier Publishing, Oxford, UK, and Cambridge, MA, ISBN 978-0-12-809272-9

Related Articles

Related Whitepapers

Sodium Hypochlorite Service Success with NETZSCH PERIPRO®

Sodium hypochlorite (NaOCl) is widely used by municipal water treatment plants Sodium hypochlorite (NaOCl) is an effective water disinfectant to treat the raw, filtered water…

Tips for the Installation of MCRT® Torquemeters

An MCRT® torquemeter must be installed properly as an integral part of a drive line network in order to achieve satisfactory operation. Proper installation will:…

Pump Solution for Recycling Food Waste

A pioneering biogas company located in central Quebec embarked on an ambitious plan to transform its business model by leveraging advanced technologies, adding new recovery…

Emissions Control System Energy Reduction with AFT Arrow

An emission control system was being redesigned by Orbital Engineering, Inc. to incorporate Variable Frequency Drive (VFD) fan systems to improve system efficiency in light…


Leave a Reply

Your email address will not be published. Required fields are marked *