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Semi Metallic Gaskets

William Johnston & Company Limited offer semi-metallic gaskets which are designed to feature soft, pliable sealing materials with lower overall load requirements when compared to fully metallic gaskets.

There are different styles of semi-metallic gasket to choose from:

Spiral Wound Gaskets are very suitable for applications featuring heavy operating conditions & where high integrity is required. They can be used for sealing flange joints, manhole and handhold covers, tube covers, boilers, heat exchangers, pressure vessels, pumps, compressors and valves etc. 

Main features:-
High integrity sealing for various applications
Available in standard and non-standard configurations
Various metals and fillers available
Kammprofile Gaskets are the preferred gasket solution when improved sealing and safety performance is required. Metal gaskets with serrated faces have proven to be very effective for sealing flange connections, particularly for applications where high temperatures, pressures and cycling conditions are encountered.

Main features:-
Suitable for a range of chemicals.
Suitable for use in high pressure and high temperature applications.
Can be refurbished and reused.
Can be manufactured to suit standard flange applications and vessels.
Can be manufactured for use with narrow flanges.
Low sealing stress required for installation.
Corrugated Metal Gaskets comprise solely of metal and do not contain any non-metallic filler in their construction. The temperature limitation of the gasket is only affected by the metal selected.

Main features:-
Suitable for uneven or distorted sealing surfaces.
Offer a more elastic material with better sealing performance.
Used on low-pressure applications usually in large diameter flue gas ducts at high temperatures.
Metal Jacketed Gaskets are particularly suitable for sealing the flat surfaces of heat exchangers, pipe flanges, boilers and process equipment. The metal outer jacket protects the inner soft resilient filler from corrosive substances, pressure and temperature. They are manufactured from a wide range of soft metals with or without filler.

Main features:-
They are all custom made so there are few limitations regarding size and shape.
The jacket provides mechanical strength to contain the filler and improves chemical resistance.
Unique construction provides stability and ensures trouble-free handling and installation.
Can be manufactured to suit narrow flanges.
Metallic Insert Gaskets offer special protection against blowout when sealing critical or dangerous substances. The austenitic stainless steel inner eyelet offers excellent protection for the soft gasket material against erosion and corrosion, while it also prevents contamination towards the medium within the pipeline.

Main features:-
Blow out protection.
Protection against chemical attack.
Improved sealability due to the local higher stress under eyelet.

Although we do not consider maximum temperature or pressure in isolation the charts below give an indication as to the maximum possible temperature assuming no pressure and maximum possible pressure assuming no temperature.

Semi Metallic Gaskets

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Contact William Johnston & Company Limited

For more information about our Semi Metallic Gaskets that are available world wide, contact us on +44 (0)141 620 1666, Email us or simply complete our online Enquiry Form.

Please note, failure to select the correct materials or products we supply (“the Products”) may result in damage to plant, equipment or property. In some instances, it may cause death or personal injury. We are not designers and do not give advice about design related matters concerning the Products. We can help and assist with the technical specifications for the Products. In specific applications, particularly where critical conditions exist, we will try to assist you within the limitations of the services that we offer. All information supplied by us is intended as technical co-operation outlining the specifications of the different Products which we supply. To the extent permitted in law, no warranty is given in respect of any information supplied by us. The customer must satisfy themselves as to the suitability of the Products for their intended application and use. The correct fitting of Products is the responsibility of the customer. Your statutory rights remain unaffected. Save in respect of death, personal injury or fraud, our entire liability to you, however arising from the supply of Products shall be limited to the £10M indemnity amount provided by our insurers.

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