What is the trigger valve kit for the Bostitch model SX1838K stapler? Support October 03, 2020 18:16 The trigger valve kit # for the SX1838K is TVA15. You mayorder it online here: Purchase Bostitch Parts Here #TVA15 Related articles My Bostitch pneumatic tool leaks air from the trigger area when I actuate the trigger, and the tool will not cycle. When the trigger is released, the leak will stop. What are the most common causes? Comments 0 comments Please sign in to leave a comment.