Secondary Seal

The secondary seal reduces the evaporation losses of the primary seal and it also prevents 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 specic bolt pitching. The overlapping of compression plates gives strong sealing pressure to the tank shell. The wiper tip complies with a UV and weather resistant type of synthetic rubber and exerts a high sealing eciency. The shunts complies with API 2003.

Tube Seal

The tube containing compatible liquid is covered by a scuffband and located directly on the stored 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 attached at top and bottom 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 hydraulic pressure outwards, holding the scuffband against the tank shell and so effecting a seal.

Mechanical Shoe Seal (Scissor Type)

The spring type mechanical shoe seal has an economical and simple design. It is easy to install without hot work, such as welding, and gives good seal performance. The shoes are held in permanent contact with the tank shell and extend into the product by hanger arms. The pusher spring material 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 roof from the atmosphere.

Mechanical Shoe Seal (Counterweight Type)

The pantograph type mechanical shoe seal is the most widely used design on external oating roof tanks. 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 a panto- graph type mechanical device. The counterweight assembly and arm exert constant pressure to push the shoe against the tank shell. The continuous seal covers the vapor space between the shoe and the roof from the atmosphere.

Foam Seal (Vapor Mounted Type)

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 creat high efficiency sealing performance. TTS-FS5 Foam seal is designed for product mounted or vapor mounted type.

Foam Seal (Liquid Mounted Type)

The exible foam lled 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 polyurethane foam blocks covered by an envelope and compressed between the tank shell and the oating roof rim. The foam blocks are held down by steel plates. This product mounted type eliminates vapor area. The curtain seal prevents any vapors passing between the roof and the metal frame or hanger bar.