Abstract: Bonnet apparatus for use with fluid regulators are described. An example bonnet includes a body having a cavity to receive a loading assembly of the fluid regulator. A support structure is disposed in the cavity and extends across the cavity to increase an impact toughness or strength of the body.

Abstract: Valve apparatus to prevent contamination of a fluid in a fluid regulator are described. An example valve apparatus described herein includes a housing disposed within a fluid flow passageway of the fluid regulator to define a low-pressure side of the fluid flow passageway and a high-pressure side of the fluid flow passageway. The housing has a bore that at least partially defines the fluid flow passageway when coupled to the fluid regulator. The housing has a movable valve assembly disposed within the bore via a non-threaded connection in fluid communication with the low-pressure side of the fluid flow passageway and external threads to threadably couple the housing to an opening of the fluid regulator. A seal system prevents impurities from flowing between the high-pressure side of the fluid flow passageway and the low-pressure side of the fluid flow passageway.