FRP Watertight Tank Sump
A watertight FRP tank sump designed to help prevent water ingress around equipment above an underground tank, reducing risks of fuel contamination and equipment damage.
A watertight PSE-FRP tank sump for underground fuel-tank systems, designed to help prevent water ingress, fuel contamination and equipment damage, with vacuum-test verification.


The product was developed from PADUNGSILPA ENGINEERING's fuel-tank and service-station experience to address water ingress into tank sumps, which can contaminate fuel systems or damage installed equipment.
The sump is manufactured using the LRTM process with polyester resin and Fiberglass Reinforcement Core Combination Mat, under the ISO 9001:2015 quality-control system stated in the PSE product specification.
A watertight FRP tank sump designed to help prevent water ingress around equipment above an underground tank, reducing risks of fuel contamination and equipment damage.
Manufactured using Lite Resin Transfer Molding (LRTM) with fiberglass reinforcement for strength and consistent product quality.
Uses polyester resin specified for underground environmental resistance together with Fiberglass Reinforcement Core Combination Mat.
The product specification states an approximately 1.48 × 1.10 m, 16-sided FRP sump with a minimum wall thickness of 6 mm.
Leak tightness can be checked by vacuum testing, with the PSE work procedure showing multiple verification points during installation.
The product specification states a 5-year quality warranty, subject to the applicable project documents and warranty conditions.
The data below is based on the supplied PSE WATERTIGHT TANK SUMP specification. Project execution should follow approved drawings and project-specific purchase documents.

The existing tank sump is removed by the main contractor in accordance with project scope and safety requirements.

The existing steel collar surface is prepared and cleaned before base-sump installation.

The base sump is installed at the prepared location in accordance with the installation details.

The first vacuum test verifies tightness after the base-sump installation stage.

Piping and equipment are installed within the tank sump by the responsible piping contractor.

The corbel section is installed to complete the tank-sump assembly for the next verification stage.

A second vacuum test is performed after major sump components and related systems are assembled.

A third vacuum test is performed after backfilling to verify the completed installation.

Illustration from the PSE installation procedure showing the corbel section used during tank-sump assembly.

Used to illustrate component locations and assembly details during verification before and after backfilling.

This drawing is presented for product information. Construction must follow the approved project drawings and applicable project details.
Contact our team for product details, installation drawings, piping coordination and project scope for service-station applications.