The throttle valve is a non repairable part. In case of damage or rust, it should be replaced with a new one. For the pneumatic butterfly valve with throttle valve failure, check other relevant parts for damage, Replace if necessary.
Shanghai Dongfeng Pump Valve Factory provides: installation, requirements and instructions for pneumatic butterfly valve of ContiTech
Do not use ContiTech pneumatic butterfly valve beyond the recommended safe extension height
In order to extend the service life of pneumatic butterfly valve, please do not use ContiTech pneumatic butterfly valve below. low compression height
Do not use ContiTech pneumatic butterfly valve under the pressure of more than 0.7 Mpa.
Do not use ContiTech pneumatic butterfly valve in a twisted state