Function and Description
The PROTEGO® SI/F in-tank valve is a internal shut-off valve and protects the downstream liquid lines of storage tanks and containers in process plants in the chemical, petrochemical, and pharmaceutical industries. This valve also increases safety and operation of the equipment. These valves are also known as in-tank valves.
The in-tank valve SI/F (figure 1) consists of the housing (1), mounting flange (2), valve seat (3), valve disc (4), and sealing (5). The mounting flange is welded into the tank shell. The valve seat is replaceable. The valve seat and valve disc are lapped metallic surfaces and an additional O-ring is installed to ensure the required tightness. The spindle sealing (6) can be adjusted or replaced and is designed for a test pressure of 25 bar / 363 psi.
The external connection piece of the housing is fitted with an operating valve, which is supplied by the customer, and is used for normal operation. The internal safety valve is kept open during normal operation. It is only closed in the event of a longer operation interruption, in an emergency, or for necessary repairs.
It is closed by an “internal sealing“, i.e., the valve is closed inside of the tank. This prevents the tank from leaking even if external components or leaks in any connected pipelines are destroyed.
Due to the special design of PROTEGO® in-tank valves SI/F, in which only the mounting flange (2) is welded to the tank shell, almost all other parts can be replaced. Replacement of important external parts does not require draining the tank. This results in significant operational advantages.
The PROTEGO® SI/F is available in various nominal sizes and materials. As an option, the in-tank valve can be equipped with an internal nozzle (7) for mounting a suction and filling pipe or a swing pipe system (SI/FA).
Tank shut-off valves of this type are usually operated manually. Versions with an explosion-proof electric actuator for direct or remote control are also available.
For special tank designs (e.g., full containment tank system), special versions with pneumatic control (PROTEGO® SI/DP) can also be supplied.
Dimensions
DN | a | b | c | d | e | f | g | h | i | k | m | n |
50 / 2" | 371 / 14.61 | 75 / 2.95 | 170 / 6.69 | 240 / 9.45 | 205 / 8.07 | 14 / 0.55 | 30 / 1.18 | 305 / 12.01 | 250 / 9.84 | 54 / 2.13 | 200 / 7.87 | 8 |
65 / 2½" | 400 / 15.75 | 85 / 3.35 | 190 / 7.48 | 305 / 12.01 | 205 / 8.07 | 14 / 0.55 | 30 / 1.18 | 305 / 12.01 | 240 / 9.45 | 45 / 1.77 | 200 / 7.87 | 8 |
80 / 3" | 416 / 16.38 | 90 / 3.54 | 200 / 7.87 | 330 / 12.99 | 230 / 9.06 | 14 / 0.55 | 30 / 1.18 | 330 / 12.99 | 290 / 11.42 | 53 / 2.09 | 200 / 7.87 | 8 |
100 / 4" | 434 / 17.09 | 100 / 3.94 | 225 / 8.86 | 270 / 10.63 | 230 / 9.06 | 14 / 0.55 | 30 / 1.18 | 330 / 12.99 | 270 / 10.63 | 40 / 1.57 | 200 / 7.87 | 8 |
150 / 6" | 658 / 25.91 | 130 / 5.12 | 320 / 2.60 | 410 / 16.14 | 370 / 14.57 | 18 / 0.71 | 40 / 1.57 | 505 / 19.88 | 440 / 17.32 | 78 / 3.07 | 400 / 15.75 | 12 |
200 / 8" | 725 / 28.54 | 145 / 5.71 | 365 / 14.37 | 540 / 21.26 | 405 / 15.94 | 18 / 0.71 | 45 / 1.77 | 540 / 21.26 | 450 / 17.72 | 68 / 2.68 | 400 / 15.75 | 12 |
Material selection
Design | A | B |
Housing | Steel | Stainless Steel |
Valve seat | Stainless Steel | Stainless Steel |
Valve disc | Stainless Steel | Stainless Steel |
Spring | Stainless Steel | Stainless Steel |
Bushing | PTFE | PTFE |
Hand wheel | Aluminium | Aluminium |
Spindle sealing | PTFE | PTFE |
Mounting flange | Steel | Stainless Steel |
Data Necessary for Specification
Stored medium
Tank height (m or ft)
Tank material
Connection diameter of drain pipe, DN (mm or inch)
Selection and Design
Together with the customer our engineers design and specify the valve for each specific application. The relevant plant specifications are taken into account when defining the required nominal sizes and connection types. Also the operating temperature and resulting special operating conditions may require special materials. The mounting flange material must be compatible with the tank material. If there are special requirements for the valve or operating parameters please contact us: If necessary we will arrange for special designs.
Flange connection type
EN 1092-1; Form B1 | andere Anschlüsse auf Anfrage |
ASME B16.5 CL 150 R.F. |
Design Types and Specifications
Two designs are available:
In-tank valve, standard design | SI/F |
In-tank valve with internal connection nozzle (7) | SI/FA |
Bei besonderen Tankkonstruktionen (z.B. Doppelmanteltank) können auch Sonderausführungen (PROTEGO® SI/DP) zur Anwendung kommen.
PROTEGO® SI/F

PROTEGO® SI/FA with internal connection nozzle

