Feature overview

1.Easy and safe to open the lid. Using the special mechanical structure to avoid accident.

2.Auto-hold at the various position and prevents the tiny rubbish to drop down.

3.Easy specification of the balancer can apply to the different lids.

4.Easy to adjust the torque with the visuality function, constant power can be worked with in the usage.

5.Easy to assemble. The design of integrative structure and the special spring make it completely free maintenance.

6.Opening the lids aslant can be allowed, the maximum oblique angle of W10-W50 is 40 and the maximum obligue angle of W70-W350 is 30, it depends on the torque calculation under the different oblique angle.

Product Parameters

Installation and commissioning instruction

1.Confirm the minimum gap between the base and the top cover, then measure the minimum distance between the cover and the base.

2.Make sure the COB (Connection panel Of the Balancer) and the COc (connection panel of the top cover) are parallel to each other. please use the horizontal adjustment bolt or install the auxiliary washer.

3.According to the size of the base and top cover, making-off the COB and cutting.

4.Welding the cOB, the base plate of top cover and the preassembled accessory together.

5.Confirm the welding strength then do the preliminary test.

5.1 Open the top cover to the position with maximum angle

5.2 For w10-w5o, Rotate the torque adjuster to the opening direction, enhance the pre-torque and screw the bolts firmly.

For w70-w350, Rotate the torque adjuster into the adjustment hole in order of (1)- (2), fix and enhance the pre-torque.

5.3 Under the condition of protection, please close the top cover. Also it should be hold between 10-20° smoothly otherwise please retry the Step.5.2 again.

5.4 Welding and make sure the welding strength quality, rubbing down smoothly.

6.Fine-tuning the opening cover angle (horizontal adjustment bolts) if need.

7.For it needs to keep opening statue or person need to operate into the lid during the working process.After the top cover is opened completely, secure the bolts in the anti-dump spout.

Usage Instructions for Manhole balancers

1. Installation Guidelines

Proper installation is critical for reliable performance. Steps typically include:

Positioning the Balancer: Align the balancer with the hinge side of the manhole cover.

Mounting: Use bolts, brackets, or welded joints to secure the balancer to both the frame and the cover.

Checking Alignment: Ensure the cover opens smoothly without uneven stress on the hinge or balancer arm.

Capacity Matching: Select a balancer rated for the cover’s weight. Undersized balancers will fail prematurely.

2. Operating Instructions

Opening the Cover: Apply gentle upward force. The balancer will counteract the majority of the weight, allowing smooth lifting.

Holding the Cover Open: Once fully opened, the balancer locks or stabilizes the cover in position, preventing accidental closure.

Closing the Cover: Apply steady downward pressure. Balancers typically slow the closing motion, avoiding sudden slamming.

3. Maintenance Tips

Routine Inspections: Check for rust, cracks, or worn-out joints.

Lubrication: Apply suitable lubricant to hinges and moving parts.

Replacement of Parts: Gas-charged balancers lose pressure over time; springs may weaken after extended use. Replace components as necessary.

Cleaning: Remove dirt or debris around the hinge area to avoid obstruction.

Common Issues with Manhole Balancers

Despite their reliability, manhole balancers may develop issues due to wear, environmental conditions, or improper usage. Below are the most common problems and solutions:

1. Cover Does Not Stay Open

Cause: Gas leakage in struts or weakened springs.

Solution: Replace the balancer with one of correct capacity; always choose high-quality, corrosion-resistant units.

2. Difficulty in Opening

Cause: Misalignment during installation, or balancer not suitable for the cover’s weight.

Solution: Realign the hinge and balancer; if necessary, upgrade to a higher-capacity model.

3. Balancer Produces Noise

Cause: Friction in moving joints, lack of lubrication, or internal wear.

Solution: Apply grease to joints and check for damaged bearings. Replace noisy components if lubrication does not resolve the issue.

4. Corrosion or Rusting

Cause: Exposure to moisture, chemicals, or seawater.

Solution: Use stainless steel or coated balancers designed for harsh environments. Conduct regular anti-corrosion treatments.

5. Sudden Closure of Cover

Cause: Worn-out locking mechanism or broken balancing spring.

Solution: Immediately stop using the balancer, replace the damaged component, and test thoroughly before resuming operations.

Safety Considerations

When handling manhole covers with balancers, safety is paramount:

Always test the balancer before working under an open cover.

Never overload or force the cover beyond its design angle.

Replace damaged balancers promptly to prevent accidents.

Use personal protective equipment (PPE) when working around manholes.