Red Jacket STP replacement work on a live forecourt is almost never a new station. It is one pump that has reached the end of its service life and has to come back out of a tank well that is already there. There are only two shapes that job takes — replace the assembly, or replace the motor and keep everything above it. The two are not interchangeable, and which one applies is decided by the site, not by the catalogue.
Two jobs, one tank well
A submersible turbine pump is not one part. It is a motor with its aspiration mechanism, completely immersed, forming the flameproof enclosure; a discharge head above the tank that carries the manifold, the lifting eye, the electrical connector and the line check valve; and a coaxial column pipe between them — the inner pipe carrying the power supply cable, the outer pipe carrying the fuel.
When a site asks about a Red Jacket STP replacement, the first question is which of those three sections has actually failed. If the head and the column pipe are sound and only the motor end is finished, replacing the whole assembly throws away parts that still have years left in them and forces the tank connection to be broken for no reason. If the head is cracked, the flange face is pitted or the column pipe has corroded through, fitting a new motor underneath it only moves the failure down the pipe.
Option 1 — Replacing the whole assembly
This is the straight swap. The old unit comes out of the well and a complete Type DT-STP assembly goes back in: motor, hydraulic end, discharge head and column pipe built and tested as one unit before it is crated. The tank, the pipework above the tank and the electrical supply all stay exactly as they are.
Four things decide whether that assembly lands correctly, and all four are read off the site rather than off the old nameplate:
- The discharge head has to land on the existing tank flange. The head is the fixed point of the whole replacement — if it does not seat and seal on the flange already set into the tank top, nothing below it can be corrected afterwards.
- The column pipe length follows the burial depth. Two builds are offered: galvanized steel, or a telescopic pipe that takes up burial-depth tolerance on site without cutting pipe. The telescopic build is available on the DT-STP75 and the DT-STP200.
- The motor rating follows the number of dispensers. One submerged pump feeds every dispenser on the island, and a single unit serves up to 8 nozzles. Across the six models the range is 0.75 HP to 5 HP, 210 to 1000 L/min, at a maximum head of 29 to 30 m and a maximum pressure of 230 to 300 kPa.
- The electrical supply stays as it is. Three-phase 380 V builds run without a capacitor; single-phase 220 V builds need one, and the head has to accept the cable entry the site already uses.
Because the assembly is built to the site, the order is confirmed against four numbers: the model coming out, the tank depth, the number of dispensers it feeds, and the litres per minute needed at the busiest nozzle. Those four turn into a DT-STP model, a pipe build and a pipe length.
Option 2 — Replacing the motor only
The second case is much more common than the first. The head is sound, the column pipe is sound, the tank flange is sound, and the failure is confined to the motor end: it has burned out, it draws high current, it trips the breaker, or it no longer holds pressure at the last nozzle on the island.
Nothing above the tank has to be disturbed. The motor end is the part that lives in the product, and on the DT-STP it is the motor housing that carries the IP68 protection degree — the same seal that keeps fuel out of the winding is what keeps the enclosure flameproof. The multi-functional combined valve body above it is rated IP54.
A motor-only replacement is ordered against the unit that is already in the ground, so the identification has to be exact:
- The model on the nameplate, not a photograph of the pump. DT-STP75, DT-STP150, DT-STP150Z, DT-STP200, DT-STP300 or DT-STP500 — 0.75 HP through 5 HP.
- Single-phase or three-phase, and the capacitor that follows from it. A capacitor is only required on the 220 V single-phase builds: 450 V, 25 µF ± 5% for 0.75 HP and 1.5 HP, and 40 µF ± 5% for 2 HP. Three-phase 380 V motors run without one. The capacitor and the relay are supplied to the motor that is actually fitted, not to the model family in general.
- The parts that come off with the motor. The intake screen filter is a 304 stainless screen mounted on the pump intake, and it, the packer manifold, the line check valve and the mechanical leak detector are matched to the tank already on site rather than replaced on principle.
What both jobs have in common
Whether the order is a whole assembly or a motor, the unit goes back into a Zone 0 or Zone 1 hazardous area, so the certification has to travel with it. The Type DT-STP series is covered by type examination certificate IEP 26 ATEX 1836X for Zone 0 and Zone 1, with EAC No. KG 417/043.CN.02.01699 for the Eurasian market. A replacement pump that cannot produce the certificate for the exact model is not a replacement — it is a modification of the installation.
Both jobs also end the same way: the pump is sized against the tank, the dispensers and the nozzle flow before the order is placed, not after the crate reaches the site.
Identify the job before you order
Send the model being taken out, the tank depth, the number of dispensers and the flow needed at the busiest nozzle, and say which of the two jobs it is — whole assembly or motor only. We answer with the DT-STP model, the column pipe build and the pipe length, and confirm the match before the order is placed. If the site needs the numbers first, the DT-STP technical data is published model by model, down to voltage and capacitor.
Red Jacket and Blue Jacket are registered trademarks of Franklin Electric. Datian Machine is not affiliated with, authorised by or endorsed by Franklin Electric; the names appear here only to describe the installations our pumps are bought to replace.