Dust Collection · 2020. 7. 31. · any dust collection manufacturer’s equipment. Most of our orders are shipped within a week or two, so ... In addition to the baghouse itself,

Dust Collection Parts and Maintenance Guide

GUIDE

8300 Dow Circle | Suite 600 | Strongsville, OH 44136 | Phone: 800-334-2957 | www.slyinc.com 2

Even if the rest of your equipment is running perfectly, clogged filters can cause

your dust collector to draw inadequate amounts of air from the pick-up points of

the application, ultimately ruining the efficiency of your system. Fail to fix the

problem and the safety of your products, the health of your workers, and your

standing regarding government compliance could all be at risk. Any of these

issues could lead to a plant shutdown and halt your business.

That’s why manufacturers need to be proactive in maintaining a safe work

environment. Like with any great system, your air quality control equipment is

only as good as its weakest link, or in this case, its most underperforming part.

To keep your air quality control equipment running smoothly, you need to replace parts when they break,

become damaged, or when normal wear and tear renders them ineffective… at the bare minimum.

Before any of that happens, it’s a good idea to have regularly scheduled change-outs. These can be

scheduled anywhere from a a few months apart to every couple of years, depending on the part

and work environment (location, seasonal changes, etc.). Sly’s engineering experts can help you to

determine what schedule is right for you.

Monitoring your operating conditions for any significant changes is also important. For instance, if your

pressure drop increases above 7” of differential pressure, it’s time to have bags on order for a pending

change-out. This way, you can prevent downtime instead of waiting around for a new part to arrive.

The team here at Sly has put together this parts guide to help you navigate the parts acquisition process.

As a dust collector OEM, we have replacement bags, parts, and filters of all sizes and media for virtually

any dust collection manufacturer’s equipment. Most of our orders are shipped within a week or two, so

your plant can stay running effectively, efficiently and up to government standards.

Maintenance ChecklistAfter selecting the right dust collection equipment, proper installation, operation, and maintenance is critical for the

safety of your workers and air pollution control. For optimal system reliability and performance, Sly recommends a

consistent schedule of inspections and the timely repair of damaged or malfunctioning equipment. This checklist

provides a sample periodic maintenance program for all styles of dust collectors that you can use as a guide to help

tailor your own programs. To see a more detailed and comprehensive list, click here.

1. Pressure Drop: Pressure drop, or differential pressure across the filter media, is a good indicator of the amount

of dust your filter is accumulating and, if regularly monitored, the condition of your bags. As the bags develop

an excessive dust cake, particulate will embed itself into the inner fibers of the filter media, increasing the pres-

sure drop. While this can offer a higher efficiency of dust collection, it causes bleed-through or binding of the

filter media. Maintaining a daily log of a baghouse's differential pressure change will give you visibility of, and

allow you to diagnose problems that may occur, or even prevent them.

2. Cleaning System: Effective cleaning systems help prevent an excessive amount of dust from building up on

your bags. Without them, you’ll see increased pressure drops, a reduced volume of ventilation air at the pick-up

points, and reduced airstream velocities. This could choke the entire system, rendering it ineffective. For those

reasons, these systems require more than just periodic monitoring. Every component of your cleaning system

must be regularly inspected, with all corrections made as soon as possible.

One part can make

all the difference

https://info.slyinc.com/hubfs/White%20Papers/SLY_BagHouseMaint_Chklst_Final.pdf


3. Hopper Discharge: Material buildup in a hopper can lead to dust accumulating as a solid mass, requiring

intensive labor and downtime to correct. As such, your material discharge methods should be inspected

frequently, as well as at shut-down times and during bag changes.

4. Visible Emissions: Visible emissions discharged from exhaust stacks indicate a breach in a seal or a broken/

torn filter bag. These emissions can cause health concerns, damage property outside the plant, and may result

in monetary fines imposed by the EPA. Dust collectors should be continually monitored, both with visual

inspections and Broken Bag Detectors, as any leaks must be located and corrected immediately.

5. Exhaust Fan: Exhaust fans are required to move ventilation air from the point of pickup, through the filter

media, and out the exhaust stack. When exhaust fans have loose/worn belts or an imbalanced impeller, they will

not exhaust the volume of air they were originally designed to handle, and your system won’t operate effectively.

You should perform thorough fan inspections on a semi-annual basis and contact the original manufacturer any

time you observe unusual vibrations, squealing, or other obvious changes from standard operation.

6. Filter Media: The most important item in a baghouse is the filter media since it allows for dust cakes to accumulate,

which provide high filtering efficiencies during operation. Too high of a pressure drop can cause excessive caking

or filter bag blinding, so periodic inspections of the filter bags/cartridges are mandatory. Make sure to inspect the

clean air side of the baghouse for leaks and the bags for tears.

7. Structural Integrity: Beyond affecting system performance, the structural integrity of your equipment can

cause health concerns and reduce equipment life. A comprehensive inspection should be done annually,

including welds, joints, and flange seals.

8. Auxiliary Equipment: In addition to the baghouse itself, thorough system inspections include a check of all

miscellaneous complementary equipment, including exhaust fans, rotary airlock valves, inlet/outlet dampers, etc.

9. Ductwork: Ductwork allows particulate to reach the baghouse. Standard practices suggest a minimum air-

stream velocity within any duct of 3500 feet per minute (fpm), and between 4000-4500 fpm for heavier dusts,

such as sand. If these velocities aren’t reached, dust tends to accumulate in the ducts, choking the system. This

increases the pressure drop in the system and its energy requirements, resulting in reduced ventilation air at the

pick-up points. To prevent this, periodically inspect the entire length of your ductwork for accumulated dust and

clean it out before it becomes a problem.


Changing Out Your FiltersThe health of your filter media will directly impact the performance of your dust collection system. When new filters

are first installed, the filter media captures dust particles, allowing clean air to pass through. While some dust cake

build-up is essential for fine particulate collection, the constant dust loading and pulsing cycle breaks down the media

over time, causing higher pressure drop and decreased system efficiency.

Effective cleaning systems will help to slow down and reduce this effect by regularly removing dust from the surface

of the filters, often with a pulse of compressed air. However, this will not stop your filters from eventually getting

overloaded with dust. When that happens, you must take the filters out and replace them in order to restore your dust

collector to proper working order.

Key Dust Collection Replacement PartsSly offers a wide variety parts with different designs, sizes, and materials that can be tailored to fit your dust collection

equipment. These are our key products to keep your operating running smoothly:

Filter Bags

Filter bags are your go-to filter medium for dust collectors, collecting unwanted particulates

as air passes through them. They are typically made of woven or felted material like polyes-

ter Nomex® (aramid), polypropylene, cotton and many other fibers. When efficiency drops

below acceptable levels, it is time to change-out your filters. Every application is different,

so you will need to monitor your pressure drop across they system to know when this time has arrived. After your first

set of filters in a new baghouse or with a new type of media, you will have a better idea as to how long your filters

will last barring any unforeseen circumstances or upset conditions, at which time the filter bags may need replaced

immediately. Most bags are shipped within a couple weeks of ordering. For details on the available filter media and

finish options, see page 5 or click here.

Filter Cages

Filter cages provide support for your filter bags and effect your filter’s efficiency. Most

are constructed of 11-gauge galvanized wire, though special 304 and 316 stainless steel

and epoxy-coated cages can be designed to meet more demanding applications. Cages

typically last several years and should be replaced if they become excessively corroded or

damaged. Sly manufactures most cage styles and sizes that are typically shipped within a couple weeks. Filter cage

compatibility is directly associated with the type of bag used.

Cartridges

Cartridges can be used as filter media instead of bags in some dust collector applications.

Designs are frequently made from spun bond polyester or cellulose/polyester blends. Like

filter bags, they should be changed out every year or two, depending on application and

unless problems arise. Most designs can be shipped within a week or two of ordering.

Cartridges are great for applications where there is relatively low dust loading and system gas temperatures remain at

250 °F (121 °C) or less. Sly can also fabricate custom cartridges if you provide a sample or design specifications.

Timer Boards

Digital timers are used to turn on and off parts of the dust collector cleaning cycle at

set intervals, allowing you to automate your system. These are perfect for pulse jet dust

collectors. Most boards are stocked for immediate shipping.

https://www.slyinc.com/products/fabric-filter-media-options/


Solenoid and Diaphragm Valves

Solenoid valves allow for an air pressure relief in order to activate a compressed air device,

such as a diaphragm valve. When combined with a solenoid valve and controlled by a timer,

diaphragm valves will send a pulse to a row of bags. Shipment for either type of valve

typically occurs within two days of ordering.

Valve Repair Kits

Pulse valve repair kits allow you to fix minor wear issues associated with your valves.

It’s good to always have a new repair kit on standby to help address any sudden issues

that could render your system ineffective. Shipment typically occurs within two days

of ordering.

Type Common Finishes Operating Temp. Common Applications Key Features

Cotton flame retardant 180°Fcleaning rooms, atmospheric air cleaning, woodworking, cement and rock products

resistant to flex and flat abrasion, excellent clean-down

Polyester singed, glazed, oleophobic 275°F cement plants, electric furnacesgreat resistance to chemicals, abrasion, dry heat degradation

Polypropylene singed, glazed, SlyTech-01 170°Fgeneral applications where chemicals and moisture attack other fibers

high strength, excellent resis-tance to most acids and alkalis

Nylon singed, glazed 250°F highly abrasive dustgood resistance to alkalis, holds up well to organic solvents

Acrylic singed, glazed, SlyTech-01 275°F dryers, mixersgood acid, heat, and hydrolysis resistance

Aramid* singed, glazed, SlyTech-01 375°Fhighly abrasive dust, electric arc furnaces, high-temp dryers, cupolas, high-temp chemicals

good resistance to alkalis, holds up well to organic solvents

Fiberglass*acid resistant, ePTFE membrane

450°Fcement kilns, high-temp dryers, carbon black reactors, power plants, electric furnaces

excellent resistance to most acids

P84®*PTFE membrane, singed, glazed, SlyTech-01

500°Fsmelters, dryers, coal-fired boil-ers, incinerators, kilns, calciners

non-flammable, resistant to flex abrasion

PPS*PTFE membrane, singed, glazed, oleophobic

375°F

coal-fired boilers, incinerators, fluidized bed systems, cement mills, oil and gas firings, asphalt plants, pulverized coal injection systems

excellent resistance to both acids and alkali, great in applications where emissions standards are tight

Teflon®* PTFE membrane, glazed 500°Fcoal-fired power plants, cement production, steel foundries

great chemical resistance and abrasion resistance

*considered high temperature media, best suited for applications with high heat operating conditions

Filter Bags

There are countless types and styles of filter bags. Listed below are the main types that Sly offers, along with a matrix

breakdown of their features and best-suited operations. For additional information on filter media, click here.

In addition to the above, Sly also offers Sly High Efficiency Felts (SlyHe), available in both regular and high

temperature (Aramid) applications. Our high efficiency felts have several advantages over both commodity felts

and PTFE membrane laminates, including higher efficiencies, lower emissions, and an extended bag life.

https://www.slyinc.com/products/fabric-filter-media-options/


Essentials Parts GlossaryAbrasion Resistance: The ability of a fiber or fabric (media) to withstand surface wear.

Blinding: Blockage in a fabric or media by dust that cannot be discharged by the cleaning mechanism, resulting in

a reduced gas flow and an increased pressure drop across the media.

Change-out: Scheduled or non-scheduled removal and replacement of dirty, damaged, or clogged filters.

Collection Efficiency: The measure of a dust collector's ability to remove particulate from the inlet gas, typically

expressed in percent or emission rate (grains per cubic foot).

Differential Pressure: The difference in air pressure between the dirty air plenum (DAP) and the clean air plenum

(CAP), commonly known as the difference of pressure “across the filter bags”.

Dust Cake: A buildup of dust on filter bags that increase the efficiency of the filter media.

Dust Collector (Baghouse): An air filtration device that uses fabric filter bags to remove solid particulate

from a gas stream.

Filter Media: The permeable barrier used in fabric style dust collectors where the dust cake is supported (bag).

OEM: Original Equipment Manufacturer.

Particulate: Any airborne solid material.

ConclusionThroughout the life of your dust collection equipment, you’re going to need to replace and change-out parts as they

become damaged or simply get too old. By following the recommendations in this guide, you’ll be able to keep your

system in proper working order and help prevent any unnecessary downtime. Our expert team at Sly is ready to help

you chose the right replacement parts so that you can keep your products, and profit, flowing.

Visit our Replacement Parts page for additional information.

https://www.slyinc.com/products/replacement-parts/https://info.slyinc.com/hubfs/White%20Papers/SLY_BagHouseMaint_Chklst_Final.pdf

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Dust Collection · 2020. 7. 31. · any dust collection manufacturer’s equipment. Most of our orders are shipped within a week or two, so ... In addition to the baghouse itself,

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