Packing is a simple but cost-effective way to minimize leakage from around pump shafts. Over time though, it needs periodic adjustment to take up wear. Eventually, when the pump packing material no longer seals effectively, it must be replaced.

This blog provides an overview of packing and discusses the options for pump packing materials.

Sealing Around the Shaft

A fundamental challenge in pump design is to prevent the fluid being pumped from escaping along the impeller shaft. Mechanical seals are an option, but they add complexity and cost. As a result, most pumps rely on compression packing.

Packing involves surrounding the shaft with a braided, rope-like material. This is pushed into a region of the pump housing called the stuffing box. A cylindrical packing gland is passed over the shaft and used to compress, (or stuff), the packing material around the shaft. The gland, sometimes called the follower, is bolted into place to maintain compression on the packing. As the packing wears, these fasteners are tightened to maintain the seal.

Friction, Heat and Leakage

As the packing material presses against the shaft, rotation generates heat from friction. To prevent overheating, the packing gland is tightened to a level that allows a very small leak. Thus the fluid being pumped the both lubricates and cools the packing-shaft interface.

This creates two challenges: the packing material must withstand sliding contact with the shaft, and it must also have appropriate chemical compatibility.

Options for Pump Packing Materials

The principal material choices are fabric reinforced rubber and graphite. Homogeneous rubber with no reinforcement works in some applications while expanded PTFE with graphite fiber is used in others.

At Hennig Gasket & Seals we carry a wide range of Garlock pump packing materials. Their Chevron® line has solutions for most packing needs, while for abrasive liquids Garlock SLUDGE-PAK® is often the answer.

Packing material selection is driven by shaft speed in surface feet per minute, and fluid type and temperature. For advice on what will suit your application, please have this information to hand when you contact us.

Garlock is one of the best-known brands in gasket materials and they have an extensive range of products. Here we’ll take a look at one of their materials that’s suitable for a wide variety of applications: Garlock Blue-Gard 3000.

Garlock Blue-Gard® 3000 Composition

The spec sheet tells us Blue-Gard 3000 is composed of aramid in an NBR binder. Here’s what that means.

The word “aramid” is a contraction of the chemists’ term, aromatic polyamide. It’s a generic term for high strength fibers produced from PPTA (poly-p-phenylene terephthalamide) polymer. You may recognize one of the widely used brand names: Kevlar.

In gasket material, these fibers need holding together. That’s the job of the NBR or nitrile rubber. NBR also provides the elasticity and compressibility we look for in a good gasket material.

Properties of Blue-Gard® 3000 Gasket Material

Aramid is very strong with excellent abrasion and creep resistance. It doesn’t melt or burn, even at very high temperatures, and it resists attack by solvents and oils. It will however degrade with prolonged exposure to UV light.

NBR is limited in the maximum temperature it can tolerate and is attacked by ozone as well as ketones, esters, aldehydes, and chlorinated hydrocarbons. Two examples of chemicals it should not be exposed to are acetone and benzene.

Where NBR excels is in resistance to oils, including those used in hydraulic systems, as well as fats and greases. When exposed to these oils it will swell. It also has good elasticity but will creep under load.

Garlock 3000 combines the most useful properties of aramid and NBR. It can tolerate 400°F (205°C) and has excellent creep resistance, which makes for good torque retention. Good strength means it withstands high internal pressures and it also resists attack from a wide range of oils.

When (And When Not) To Use Blue-Gard® 3000

Good uses are for sealing water, oils, and greases, even those being moved at high temperatures. Applications involving thermal cycling will benefit from high creep resistance. Applications to avoid are those with exposure to ozone, (such as high voltage electricity,) as well as perfumes and foodstuffs.

Hennig Gasket & Seals is the preferred vendor of Garlock Blue-Gard® 3000 and all other Garlock gasket material.  Contact us today for a quote on custom cut Blue-Gard® gaskets or sheets of Garlock gasket material.

Everyone has favorites – favorite teams, favorite food, and some of our customers have a favorite gasket material manufacturer. At Hennig Gasket we want to give customers the gasketing solution that meets their needs, which is why we stock material from all the leading manufacturers.

“Leading” is key. We’re not going to sell you a material or product that will disappoint, so we’re particular who we deal with. The materials we stock and distribute come from established manufacturers with long track records and deep understanding of sealing and gasketing. One of those manufacturers, and certainly one of the best known, (customers ask for it by name,) is Garlock.  Hennig Gasket is a stocking distributor of all Garlock Gasket Material.

About Garlock

Part of EnPro Industries, who specialize in engineered industrial products, Garlock is in the business of sealing fluids and protecting pipelines. They manufacture around the world, including in the US, and their products are used in industries ranging from food and pharmaceuticals to petrochemicals.

Technology-Driven

Garlock prides itself on the quality of application engineering (AE) support provided, and backs that up with extensive testing and product development capabilities. They continually invest in their production facilities and use R&D to ensure a steady flow of new product innovations.

Non-Asbestos Sheet Gasket Material

We carry two lines of Garlock compressed gasket material: Blue-gard and the Garlock 9000 series. The Blue-gard sheet materials consist of aramid heat-resistant synthetic fibers, fillers, and an elastomeric binder. This can be SBR, NBR, EPDM or neoprene. The 9000 series materials are similar but replace the aramid with carbon fibers. The 9800, 9850 and 9900 all handle continuous maximum temperature of 650°F.

Why Garlock?

When replacing a gasket it’s usually a safe strategy to make the new gasket the same as the old. As Garlock gasket material is among the most widely used, it makes sense to stay with that, unless it wasn’t performing.

Global reach means Garlock gasket material is available around the world. That’s useful for multinational manufacturers wanting to standardize on their gaskets: they just have to ask for Garlock.

Garlock are undisputed experts in sealing technology and have AE facilities second-to-none. When a joint proves particularly difficult to seal they have experts who can usually find a solution.

You don’t stay in business a long time without being dependable, (and at Hennig we’ve 90 years experience to back that up!) Garlock has been around a long time too, and we believe that speaks to their reliability and customer focus.

If You Want Garlock Gasket Material …

… we’ve got it. We know Garlock is a favorite of many of our customers, and they make a quality product. That’s why we’re happy to offer Garlock gaskets and gasket materials.