Mechanical Shoe Seal (Pantograph Type)
The pantograph type mechanical shoe seal is the most widely used design on external floating roof tank and provides long service life. The metallic band is formed as a series of shoes that are overlapped together to form a ring and held against the tank shell by pantograph type mechanical device. The counterweight assembly and arm exerts a constant pressure to push the shoe against the tank shell. The continuous seal covers the vapor space between the shoe and roof from the atmosphere.
Mechanical Shoe Seal
This spring type mechanical shoe seal has an economic and simple design. It is easy to install without hot work, such as welding, and gives good performance for sealing.
The shoes are held in permanent contact with the tank shell and extend into the product by hanger arms. The material of pusher spring is high tensile stainless spring steel and springs push the shoe at two positions, upper and lower.
The vapor membrane covers the vapor space between the shoe and the room fro the atmosphere.
The flexible foam filled primary rim seal consists of a series of foam blocks which are covered by
an envelope and held down by steel plates. The foam blocks compressed between the tank shell and the floating roof rim effect high efficieny sealing performance.
The flexible foam filled primary rim seal is mounted in a position resulting in the bottom of the seal being in contact with the stored products.TTS-FS7 Foam Seal is comprised of a series of polyurethand foam blocks covered by an envelope and compressed bwtween the tank shell and the floating roof rim. The foam blocks are held down by steel plates. This product mounted type eliminate vapor area.
The curtain seal prevents any vapor passing between the roof and the metal frame or hanger bar.
The flexible foam filled primary rim seal consists of a series of foam block which are covered by an envelope and held down by steel plates. The foam blocks compressed between the tank shell and the floating roof rim effect high efficiency sealing performance.
TTS-FS8 Foam Seal is designed for product mounted or vapor mounted type.
The tube containing compatible liquid is covered by a scuffband and locatd directly on the sotred product. The liquid filled tube gives pressure softly to the tank shell and eliminates the space between the stored product and seal. Against the tank shell is a scuffband of nylon fabric coated with an abrasion resistant polymer coating which prevents a ribbed surface to the shell. The scuffband is sttached at top and botton by bolting in such a fashion that the lower portion of the scuffband is in contact with the stored liquid, i.e., product mounted.
The filled tube exerts a hydraulic pressure outwardsm holding the scuffband against the tank shell and so effecting a seal.
The secondary seal reduces the evaporation losses of the primary seal and it also prevents the rainwater and other products from falling into the stored product. The compression plate may be mounted on horizontal or vertical type of roof rims and is made to accept specific bolt pitching. The overlapping of compression plates gives strong sealing pressure to the taankk shell. The wiper tip complies with a UV and weather resistant type of synthetic rubber and exerts a high sealing efficiency. TTS-SS1 is available to re-entry the tank withour any damge and hang up when over filled. The shunts complies with API 2003.