Drum gaskets play a critical role in ensuring dangerous liquids and gases remain safely contained within drums during transport and storage. Selecting the proper gasket material is crucial to maintain a tight seal and prevent leaks, spills or accidental exposure. This guide will provide an overview of key factors to consider when choosing Drum Gasket Materials for your specific application.
What Are Drum Gaskets?
Drum gaskets are circular pieces of material installed between the lid and body of drums. They act as a seal to prevent leakage of the drum’s contents. Gaskets fill small gaps and surface defects, creating a tight, impenetrable barrier against liquid and vapor escape.
Common locations for drum gaskets include:
- The chime. This is where the upper curl of the drum meets the lower curl once the lid is placed on top. Chime gaskets provide a seal along the entire circumference of the drum.
- Bung openings. Bung hole gaskets seal threaded bungs that allow for filling and emptying of drum contents.
Gasket materials must be chemical-resistant and maintain sealing properties across a wide temperature range to accommodate liquid expansion and contraction. They cushion shocks during handling to prevent seal failure.
Key Factors in Choosing Drum Gasket Materials
There are several key considerations when selecting an appropriate gasket material for your application:
Chemical Compatibility
The gasket material must be resistant to the particular chemicals or products stored in the drum. Otherwise, the gasket may degrade, shrink or swell, compromising its ability to maintain a tight seal. Always check chemical compatibility charts to avoid issues.
Temperature Resistance
The gasket must withstand temperature extremes that may occur during transport, as contents expand and contract. Ensure the material retains sealing properties across expected temperature ranges.
Elastomer Type
Elastomer gasket materials include Natural Rubber, Nitrile(NBR) Rubber, EPDM, Silicone Rubber, FKM(Viton), Neoprene and others. Choose an elastomer compatible with drum contents and suitable for expected temperatures.
Gasket Style
Various gasket styles exist, such as flat gaskets, ring gaskets, or molded O-ring gaskets. The right style depends on drum and lid design, desired level of vapour seal, reuse requirements and other factors.
Choosing Chime Gasket Materials
The chime gasket is critical for providing a leak-proof seal along the entire circumference of drum lids. There are several material options:
Nitrile (Buna-N)
Nitrile rubber is suitable for oils, fuels, hydraulic fluids and some acids. It withstands temperatures from -30°F to 212°F. Nitrile has superior resistance versus natural rubber, but has limitations with ketones, glycol-based brake fluids and low molecular-weight acids.
Ethylene-Propylene Diene Monomer (EPDM)
EPDM rubber offers good heat resistance, up to approximately 150°C, combined with excellent resistance to weathering and ozone. It is a viable option for applications involving moderate high temperatures and outdoor exposure.
Neoprene
Neoprene gaskets provide an economical choice compatible with many chemicals across a moderate temperature range of -40°F to 200°F. They resist oils, solvents and refrigerants. Limitations include poor resistance to ketones and flame retardancy requirements.
Polyvinyl Chloride (PVC)
PVC gaskets withstand moderate temperatures up to 140°F. They offer decent resistance to acids, bases, alcohols and oils, but have limitations with ketones, chlorinated hydrocarbons and aromatic hydrocarbons. Density varies based on application requirements.
Silicone
Silicone rubber gaskets maintain flexibility and sealing across a wide temperature span from -80°F to 400°F. They resist weathering, ozone, aging, moisture, UV rays and radiation. Applications include acids, engine oil, aviation fuels and dry heat up to 500°F. Limitations occur with steam, polar solvents and chlorinated hydrocarbons.
Fluorocarbon Rubber (FKM)
FKM, also known as Viton®, is another material prized for its high-temperature resistance, along with excellent chemical resistance. FKM can typically withstand temperatures up to 250°C, making it suitable for severe operating conditions.
Polytetrafluoroethylene (PTFE)
PTFE gaskets (Teflon®) handle extreme temperatures from -400°F to 500°F. They resist almost all chemicals, solvents, acids, hydrocarbons, halogens and oils. The inert, non-stick surface prevents product adhesion. Limitations include poor cold flow properties, requiring additional sealing aids in some applications.
When selecting a chime gasket material, consult chemical compatibility charts and consider temperature requirements, cost, reusability needs and regulatory compliance standards.
Choosing Bung Gasket Materials
Proper bung gasket selection prevents leaks at filling and discharge ports. Consider factors like:
Media Compatibility
Check chemical resistance charts to avoid bung gasket degradation. Common options like Buna-N, PTFE, or nitrile sheets with fiberglass reinforcement provide broad chemical resistance.
Style
Molded O-ring gaskets allow single-use convenience, while flat gaskets enable reuse. O-rings suit applications with minimal drum handling. Flat gaskets better withstand shock and vibration from transport.
Temperature Range
Ensure bung gasket materials retain sealing properties across expected temperature extremes during transport and storage.
Elastomer Type
Elastomer O-rings include materials like nitrile, EPDM, silicone, Viton® fluoroelastomer, and more. Choose per chemical and temperature compatibility needs.
Proper drum bung gasket selection avoids content leakage, preserves product purity and maintains worker safety. Consult chemical resistance data and comply with transport regulations.
Understanding Drum Content
When selecting drum gaskets, you must also fully understand the characteristics of the contents that will be sealed inside the drums. Key factors include:
Product Physical State – Liquid, Solid or Gas
The product’s physical state influences required gasket thickness, hardness, and concentration of sealing force. For example, a thin liquid may require a softer, more pliable gasket material versus a semi-solid or powder.
Chemical Compatibility
As outlined previously, the gasket material must be completely compatible with drum contents across the total exposure period. Even minor chemical degradation can lead to seal failure.
Vapor Pressure
Higher vapor pressures require thicker, denser gasket materials to maintain an adequate seal. Content volatility also impacts gasket style – molded O-rings often suit high vapor pressure products.
Viscosity
Highly viscous liquids require more pliable gaskets that can conform around particles and residues. Low viscosity products need gaskets resistant to flow and leakage under pressure.
Operating Temperatures
Expected temperature extremes, both hot and cold, dictate the need for specific material grades that retain sealing properties across required ranges.
Reactivity
If contents may react with air or moisture, gasket permeability must be minimized. Certain materials like PTFE do not absorb liquids, avoiding potential reactivity or contamination.
Fully characterizing drum contents enables proper gasket material selection to prevent leakage, maximize safety and extend reusability. Consult compatibility charts and regulators to choose compliant, high-performance gasket materials for your specific application.
Summary
- Drum Gaskets seal chime and bung spaces to safely contain hazardous or volatile liquids and gases.
- Key selection factors include chemical and temperature compatibility, elastomer type, gasket style and compliance standards.
- For both chime and bung gaskets, ensure the material matches expected service conditions and drum contents.
- Fully understand product physical state, compatibility, vapor pressure, viscosity and other characteristics before choosing a gasket material.
- Selecting the optimal gasket material avoids leaks, preserves purity and maintains regulatory compliance.
Proper drum gasket selection requires understanding both gasket capabilities and drum contents to create an impenetrable, long-lasting seal. Following chemical, temperature and industry compliance guidelines will ensure success. With an ever-expanding array of high-performance gasket materials, processors can safely and efficiently transport even the most dangerous liquids and gases.
