Gate Valve Gland Packing, How to Tutorial by Kevin Ging

Summary

This instructional video provides a comprehensive guide on packing a valve using various materials like greasy hemp and graphite. It outlines essential tools, including packing extractors and dummy shafts, and details the step-by-step process of removing old packing, measuring and cutting new packing, and properly inserting it to ensure a leak-proof seal. The video emphasizes the importance of maintenance, advising regular adjustments to gland nuts to prolong valve life and efficiency. Viewers gain valuable insights into maintaining optimal valve function through effective packing techniques.

Takeaways

• 🔧 The valve packing process involves using materials like greasy hemp, cotton, flax, and graphite to create seals.
• 🛠️ Essential tools for packing include a packing knife, packing extractors, a dummy shaft, and an off-cut pipe.
• 📏 Correct packing size is determined by measuring the valve stem diameter and the throat of the stuffing box.
• ✂️ Packing should be cut at a scarf joint (angled cut) to ensure a better seal and prevent leaks.
• 🌀 When wrapping packing around the dummy shaft, keep it tight for proper diameter and fitting.
• 📏 Rolling out packing with an off-cut pipe helps thin it for easier insertion into the stuffing box.
• 🔄 Alternate the ends of packing strands during insertion to avoid continuous joints that could leak.
• 🔩 Leave room for adjustment when compressing packing to allow for periodic maintenance and tightening.
• 🔍 Testing the valve involves checking for leaks and adjusting gland nuts as necessary for a proper seal.
• 🕒 Regular maintenance of valve packing is crucial for optimal performance and preventing leaks.

Q & A

What type of packing is used in the valve discussed in the video?

The video discusses using greasy hemp and cotton or flax woven packing that is impregnated with lubrication grease.

What is the purpose of the packing in the valve?

The packing forms a seal between the valve stem and the stuffing box, preventing leaks and ensuring proper valve operation.

How is the packing cut for installation?

The packing should be cut at a scarf joint, which is an angled cut that allows for overlapping joints to prevent leaks.

What tool is used to extract the old packing from the valve?

A packing extractor with a corkscrew type end is used to lift the bridge and bush out of the way and extract the old packing.

Why is lubrication important for the packing?

Lubrication helps to keep the packing fresh and pliable, reduces friction, and prevents overheating and scoring of the valve stem.

What should be done if the packing is old and dry?

If the packing is old and dry, it will crack and fail to compress properly, necessitating a replacement to maintain a proper seal.

How can you determine the appropriate size of packing to use?

Measure the diameter of the valve stem and the throat of the stuffing box, subtract the stem diameter from the throat diameter, and divide by two to find the packing size.

What is the significance of layering the packing in a specific order?

Layering the packing in an alternating pattern prevents a continuous joint that could allow fluids to leak through the valve.

How is the valve prepared for service after packing is installed?

The gland nuts are tightened, and the valve is tested by spinning the hand wheel to check for leaks and ensure proper compression on the packing.

What adjustment can be made over time to maintain the valve packing?

Periodic maintenance involves tightening the gland nuts by half turns to maintain compression on the packing as it wears over time.