Vacuum Gauges

Installing a vacuum gauge on your Separ filter has many benefits:


  • VacuumGauge

    Ensures your unit is always working efficiently

          as element is clear of contamination 


  • Saves energy

          by ensuring your filter is in prime cleaning condition 


  • Cost effective

         saves on unnecessary maintenance costs and replacement elements 


The Separ gauge shows when the filter is blocking (ie removing particulate from your fuel) and thus requires backwashing, a new element or servicing.

Having this information to hand means backwashing can be completed as soon as there is evidence of a blockage, rather than the filter struggling to clean fuel through the blocked filter and potentially using more energy. Backwashing can be performed several times before an element replacement. 

Cost savings are made by only replacing elements and performing maintenance checks when necessary, rather than within a set time for example every 6 months.


How does it work?

vacuum gauge 2The red needle is manually adjustable and should be set to the same position as the black needle, when the element is clean and fuel first runs through the filter. The black active needle then shows the current vacuum reading and will increase over time as the filter removes particualte from your fuel. You are looking for a difference between the initial reading (red needle) and the current reading (black needle) of 4psi, this is approximately 270mbar.

In essence, you are reading the differential pressure (vacuum) of your filter. When this difference is reached or exceeded, a backflush or service is required.

The filter can be backflushed up to 5 times before element replacement is necessary. This procedure extends filter element life and the gauge is a clear signal for timely maintenance. As a result, elements are used efficiently and you keep costs to a minimum. Replace the element at least 1 time per year. 

Gauges can not be installed on lids that have not been tapped for it. If your existing filter does not have a gauge, you will need to replace the lid with a lid complete with gauge.


Product range


30650 Vacuum Gauge-Glycerine Filled (1/4" BSP)


Technical Specs


The vacuum gauge needs to be installed on the lid of the Separ Filter. Gauges can not be installed on lids that have not been tapped for it. If your existing filter does not have a gauge, you will need to replace the lid with a lid complete with gauge.


Technical information

vacuum techAdjustable vacuum / pressure gauge

  • -600mbar to +600mbar
  • Glycol filed
  • Tell-tale adjustable needle
  • ¼” BSP-P male thread
  • 2” dial

1. Working Pressure Limitations

  1. Dynamic Pressure. The working pressure should be limited to 60% of the dial range.
  2. Static Pressure. The working pressure, where no sharp fluctuations occur, should be limited to 90% of the dial range.

2. Ambient Temperature
-18°C to 60°C (0°F to 140°F)

Lower operating temperatures are available to -40°F (40°C) by using a special glycerine mixture or low temperature silicone.


All gauges hermetically sealed gauges with ranges of 400 psi and below, including all vacuum and compound ranges, are equipped with a vent pin in the relief disc.

The vent pin should be removed after installation of the gauge to insure accurate indication.

Need help selecting a filter?

See our guide to help you select the most suitable filter for your needs.

Technical Support

How it works

See how the Separ filter works to separate water and particulate from fuel. 

SWK2000 flow diagram transparancy

How to Order

Call or email us to place your order. We accept ALL major credit and debit cards, bank transfer and also PayPal. 

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Expert advice

Unsure which spare parts you require? Or if a Separ filter will meet your requirements? 

Talk to our expert team. Call 01923 276 007



Delivery options

We have a wide range of shipping options available to suit your destination and budget.



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Contact Us

3 Kingley Park, Station Road, Kings Langley, Herts, WD4 8GW

Tel: +44 (0)1923 276007

Fax: +44 (0)1923 267463

Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Here to Help

Product guides

Fuel Specs


Selecting a Filter