In LNG service, stem seals must accommodate thermal gradients from cryogenic process temperatures at the valve body to ambient or even elevated temperatures at the top of the extended bonnet designs commonly employed to thermally isolate external sealing and actuation components from direct cryogenic exposure that would freeze lubricants, embrittle materials, and potentially compromis... https://globalsealstech.com/product-category/oil-gas-seals/api-6d-ball-valve-and-lng-seals/