Bag Filter Maintenance

NQIS provides specialist baghouse, cartridge filter, and fabric filter services for industrial sites across the UK. We support both planned maintenance and reactive interventions, helping operators maintain emissions control, protect plant performance, and reduce unplanned downtime.

What Is Bag Filter Cleaning and Maintenance?

Baghouses and fabric filters are a critical part of emissions control systems and form the final barrier before emissions exit the stack.

When filters are damaged, poorly installed, or excessively caked, performance can deteriorate quickly. This can lead to dust carryover, elevated differential pressure, reduced airflow, and increased compliance risk. Regular inspection, cleaning, and maintenance are essential to maintain stable performance.

Our Bag Filtration System Services

Through our dedicated Fabric Filter Division, NQIS provides specialist expertise in the inspection, cleaning, troubleshooting, and replacement of fabric filter systems.

With over 25 years’ experience working with split cages, cartridge filters, and conventional bag-and-cage arrangements, our teams understand the practical challenges of maintaining filtration efficiency across a wide range of baghouse designs.

Our services include:

• Online and offline bag filter cleaning
• Full fabric filter and cartridge change-outs
• Troubleshooting emissions spikes, airflow issues, and high differential pressure
• Dye testing and leak detection
• Fabric filter inspections and condition assessments
• Inspection reports with photographic evidence and recommendations
• Cage and support system inspection
• Differential pressure (DP) assessment
• Hopper and filter unit clean-out

We work across pulse jet, shaker, and reverse air systems, adapting our approach to suit site access and operating conditions.

Fabric Filter Inspection & Troubleshooting

Even minor defects, such as torn filter media, damaged cages, or poorly seated seals, can lead to dust carryover and emissions risk.

NQIS carries out structured fabric filter inspections supported by clear, site-specific reports. Where performance issues exist, our teams provide targeted troubleshooting, reviewing airflow, pulse-cleaning effectiveness, installation quality, and system condition.

Dye testing is used where appropriate to identify leaks or emission pathways not visible during routine inspections, allowing corrective action without unnecessary full filter replacement.

Rotary Cleaning Bell

Most baghouses rely on pulse jet cleaning. Where this is no longer effective, NQIS uses rotary cleaning bells to restore fabric filter performance and reduce elevated differential pressure.

The cleaning bell is inserted into individual filter bags to break down heavy caking and blinding, allowing targeted cleaning of affected filters. Rotary cleaning can be carried out online or offline during planned shutdowns.

Full Filter Change-Outs

NQIS undertakes full fabric filter and cartridge change-outs during planned shutdowns and outages. Works are carefully planned to ensure safe access and correct installation.

This includes:

• Safe removal of spent filters
• Inspection of cages and cartridge supports
• Correct seating and sealing of replacement filters
• Post-installation checks

How Our Bag Filter Maintenance Service Works

1. Initial discussion – Review of site conditions and performance
2. Site inspection – Assessment of filters, cages, and internals
3. Scope agreed – Clear plan aligned to site requirements
4. On-site works – Cleaning, inspections, or change-outs completed
5. Handover – Systems returned to service

All works are planned to minimise downtime

Typical Sites

We regularly deliver bag filter services at:

• Quarries
• Waste-to-energy and EfW plants
• Power and energy facilities
• Factories and processing plants
• Mobile asphalt plants