Very typical PTFE wedge mechanical seals include John Crane 109, John Crane 109B, and John Crane 58U, 59U. Many times we can refer to these types of models as a reference, to have a further study about the PTFE wedge mechanical seal. We can take type 109 as an example. Type 109 is a Shaft-mounted Multi-spring Wedge Seal for use on corrosive applications, typically for chemical or hydrocarbon processing. The features of the John crane 109 mechanical seal is that the Shaft-mounted wedge seal, with PTFE or graphite-based wedges for corrosion resistance or high-temperature application. And the Parameters are as following shows:
TEMPERATURE LIMITS: -148°F to 932°F/-100°C to 500°C
PRESSURE LIMITS: 24 bar(g)
SPEED LIMITS: 25m/s
From the above example,we can see that the PTFE Wedge Mechanical Seals
are standards for use where expensive and corrosive liquids are being processed, especially for extremely corrosive fluid applications such as sulphuric, nitric, phosphoric or hydrochloric acids. Like most materials every choice has an up and a down side. Because PTFE will handle most chemical applications, chemical attack is no longer an issue. One the down side PTFE wedges
can cause fretting of your sleeve or shaft if you have not hard surfaced your shaft or sleeve (plasma coating).
A PTFE wedge seal for general low- to medium-pressure duties in the chemical, refinery, petrochemical and pharmaceutical industries. Alternative seat designs and material options are available to suit product and operating conditions of applications. Typically applications of a corrosive nature, cryogenic and high temperature.The stationary element of your seal will require a PTFE gasket
. But it's not much good to have a PTFE
on the rotary and then use an elastomer on the seat. We have seen it done, and because it is a static application some have gotten away with it, but it is not recommended. Most commonly the seat will be a L-shaped or Clamped mount style to allow space for a PTFE gasket to be used as the secondary sealing element
is committed to providing the best service and products in fluid industry. And Sealcon PTFE Wedge Mechanical Seals
can replace the mechanical seals produced by John Crane and Burgmann and be widely used in petroleum, chemistry, refinery, paper making, pharmacy, power and auto industry. We have been offering PTFE Wedge Seals
many years with emphasizing strict quality control, product reliability and product diversity. With the leading design and development capabilities, now Sealcon mechanical seals company widely cooperated with global customers and established close connection with many famous enterprises in fluid industry market.