What are common butterfly valve problems?

2026-03-20

A concentric rubber-seated Butterfly Valve mainly consists of a valve body, disc, stem, rubber seat and actuator. The disc is fixed to the stem, with their centerlines coinciding (hence the name "concentric"). The rubber seat fits closely with the disc to achieve sealing, and the actuator controls the disc rotation to regulate medium on-off. Its valve body adopts a straight-through streamline design to reduce medium flow resistance; the stem runs through the valve body to transmit torque, and the actuator (electric, pneumatic, etc.) adapts to different control needs.

composition of butterfly valve.jpg

Especially the wafer-type, this valve is widely used in low-to-medium pressure industrial and municipal fields due to its compact structure, high cost-effectiveness and reliable sealing. Common application scenarios include sewage treatment plants, HVAC systems, fire sprinkler networks, thermal power plant cooling water pipelines, marine seawater suction pipelines, as well as petroleum, chemical, gas processing industries, irrigation, district heating and slurry transfer systems, mainly undertaking on-off control and basic flow regulation of liquids, gases and low-viscosity slurries.

However, long-term operation, improper operation and harsh medium conditions easily lead to faults, mostly concentrated in the sealing system, stem and actuator. For practitioners with basic industry knowledge, mastering these typical faults and their causes is key to ensuring stable valve operation and reducing maintenance costs.

China ductile iron wafer butterfly valve factory.jpg

The common faults, performances, causes and corresponding application scenarios of concentric rubber-seated butterfly valves can be intuitively understood through the following table:

Butterfly Valve Fault Analysis

Fault Type	Fault Performance	Main Causes	Corresponding Application Scenarios
Sealing Failure	Internal Leakage	1. Rubber seat wear, aging, hardening, cracking or swelling; 2. Solid particles in the medium scratch the sealing surface; 3. Uneven flange bolt preload causes valve body deformation and poor fit between disc and seat	Slurry transfer, sewage treatment, HVAC, district heating, fire protection, marine pipelines
	External Leakage	Aging stem packing rings and damaged flange gaskets fail to withstand medium pressure	Gas, chemical, water supply and drainage, various industrial and municipal pipelines
Stem and Related Component Damage	Stem jamming, slow movement, bending, fracture; abnormal valve reversing, incomplete on-off	1. Dry friction caused by insufficient lubrication, corrosion and scaling due to medium infiltration; 2. Medium corrosion (wetted stem); 3. Undersized actuator with insufficient torque leading to stem overload	Chemical industry, corrosive processing, irrigation, water supply and drainage, thermal power plants, marine seawater pipelines, fire protection systems
Actuator Fault	Slow movement, unresponsiveness, inaccurate positioning; valve on-off jamming	Electric actuator: motor aging, gearbox wear, electrical control system failure	Automated industry, municipal pipelines, thermal power plants, industrial processing pipelines
	Abnormal movement, insufficient driving force	Pneumatic actuator: cylinder seal leakage, insufficient air supply pressure; seat-disc adhesion due to long-term idle standby valves	Petroleum and gas fields, fire protection and marine emergency pipelines
Improper Operation/Installation (Inducing Factor)	Accelerates various faults and aggravates component wear and deformation	1. Forced connection of misaligned pipelines; 2. Long-term use of valves as throttling devices; 3. Over-tightening of packing gland bolts	All application scenarios, especially irrigation, district heating, chemical industry, slurry transfer, water supply and drainage, gas pipelines

It should be noted that the rubber valve seat is usually made of EPDM or NBR, suitable for water, gas and weakly corrosive chemical media. As a core sealing component, its wear rate is closely related to medium conditions and operation frequency.

Most faults of concentric ductile iron butterfly valves can be prevented through standardized maintenance and correct operation. In high-wear scenarios such as slurry transfer, regularly check the rubber seat for wear and aging and replace damaged components in time; for automated Electric Butterfly Valves, lubricate the stem and bearings promptly to ensure smooth operation; correct installation and standardized on-off operation in all scenarios can also greatly extend the valve's service life.

When faults occur, targeted solutions can be adopted: replace damaged rubber seats and packing rings, repair or replace worn stems, and calibrate the actuator. Mastering these common faults and their causes helps practitioners quickly diagnose problems and take effective measures to ensure stable and efficient operation of pipeline systems in municipal, industrial, marine, fire protection and other fields.