Type S Tubing Drains
Type S tubing drains — Engineered for Oilfield Production
Tri‑Alta Type S tubing drains provide a controlled method of fluid release within the tubing string. The design allows fluid equalization without mechanical manipulation, supporting safer and more efficient well servicing operations.
Large drain ports allow rapid fluid movement, supporting pressure equalization in heavy crude and other demanding fluid conditions. This helps reduce risks associated with pulling wet tubing, including safety hazards and unnecessary handling.
Installation and Configuration
Type S tubing drains are installed within the tubing string at a defined depth, typically configured box-up and pin-down. Placement is determined based on operating conditions, pressure considerations, and system requirements.
Shear screw configuration is used to control activation pressure. Selection is based on calculated depth and desired shear value, with configuration adjusted to align with operating requirements while maintaining tubing integrity.
Proper configuration supports reliable activation while avoiding excessive loading on the tubing string.
Component Overview
Material and Construction
Tubing drains are manufactured from alloy materials selected for durability and performance in oilfield environments. Brass shear screws are used to provide predictable and controlled shear characteristics.
Component design supports consistent operation under pressure and compatibility with standard tubing configurations.
Replacement components are available to support maintenance and continued operation.
Performance Considerations
Tubing drain configuration is influenced by factors such as tubing size, operating depth, fluid characteristics, and pressure requirements. Proper selection of shear screw quantity and rating ensures the drain activates as intended under defined conditions.
Shear Screw & Seal Detail
Application Support
Tri‑Alta provides application support to assist with tubing drain selection, shear configuration, and integration with your tubing string and operating conditions.
Shear Screw Quantity
Nominal brass shear values by tubing size and screw count.
| Tubing Size | Shear Screw Quantity | |||||
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | |
| Nominal Brass Shear Value (PSI) | ||||||
| 2-3/8" EUE | 975 | 1950 | 2925 | 3900 | 4875 | — |
| 2-7/8" EUE | 875 | 1750 | 2625 | 3500 | 4375 | 5250 |
| 3-1/2" EUE | 750 | 1500 | 2250 | 3000 | 3750 | 4500 |
Setting the drain: multiply the setting depth in feet by 0.433 and add 1000 psi as a safety factor. Select the number of brass shear screws that at least equals the calculated value, using only the minimum number required to avoid over-pressuring the tubing.