Graver Primary Tank Seal (GVR)

The Graver Primary Tank Seal (GVR) is suitable for both external floating roofs and internal pan decks. This seal has been successfully used on tanks across a wide range of diameters, storing the full spectrum of crude and refined products, though it is not typically recommended for waxy crudes.

The Graver Primary Tank Seal (GVR) is designed for top-of-roof installation and removal, simplifying maintenance. Its sealing effect between the roof and the tank shell is achieved through specially designed octagonal foam sections, securely held in place by an internal hold-down plate.

The operational position of the seal, whether in contact with the stored product or slightly above—is determined by the top bolting configuration. The foam sections and hold-down plates are encapsulated within a synthetic rubber envelope made from highly abrasion-resistant coated fabric. This provides a soft yet highly efficient sealing effect while ensuring long-lasting performance.

Optional weather shields can be fitted to reduce rainwater ingress, though in recent years, secondary seals have proven to be a more practical and cost-effective solution. When installed in contact with the stored liquid, the Graver Foam Seal delivers excellent sealing efficiency, helping to minimise product loss and maintain tank integrity.

Material Specification:

Two alternative standard envelope materials are generally used:
– Polyurethane Coated Nylon fabric 1.0 mm. thick
– PVC Nitrile elastomer coated Nylon fabric 1.5 or 2mm mm. thick

Service life:
8 – 20 years

Typical weight of complete seal:
20 kg per linear meter

Technical data:

Rim space:
200 mm ± 100 mm (standard)

Aromatic resistance:
100%