4. Dismantle the electric butterfly valve of JA type damping butterfly valve to make it stand upright, clamp the lower connecting ring on the bench clamp, and pull and press the shock absorber rod several times. At this time, there should be stable resistance. The resistance of pulling up (restoring) should be greater than the resistance of pressing down. If the resistance is unstable or no resistance, it may be the lack of oil inside the electric butterfly valve or the damage of valve parts, Repair or replace parts>Dongfeng environmental protection tenet: adhere to the principle of "product quality is assured and service reputation is satisfied", continue to devote to electric butterfly valve with new mechanism and new starting point, strive to improve their own quality, enhance market competitiveness, and remain invincible in the electric butterfly valve industry