Mechanical Seals: Green in More Ways than One

Mechanical seals are the future of manufacturing due to their longevity, efficiency, and lower long term costs. As environmental regulations ramp up year by year, it’s best to always aim for the most eco-friendly solution to your manufacturing needs. It will save you money in the long run and prevent any headaches of having to transition when new regulations come around.

Loss of Product

The primary benefit of mechanical seals is that they are much more effective at retaining product than traditional gland packing. Normally, packing material is placed around where a shaft and its housing are joined, stuffing any leaks. Over time packing material degrades, also damaging the pump, causing inevitable leakage. With so many materials requiring zero-loss in regards to the environment, these methods are no longer viable. This leakage also causes loss of revenue due to spilled product.

On the other hand, mechanical seals work by creating three sealing points. The most important and intricate portion of the seal is the middle portion where the rotating and stationary portions meet. This section must be lubricated enough to rotate, but tight enough not to allow any leakage, which is the primary concern when dealing with the environmental regulations. These surfaces are microscopically flat, ensuring a tight seal so that fluid cannot escape.

Mechanical seals can also be designed to prevent emissions in the air. A properly engineered and installed mechanical seal will eliminate virtually all leakage and waste. It is important to regularly maintain and inspect these seals, as when they fail it tends to be more catastrophic than the gradual decay of gland packing. Double sealing systems can prevent this kind of large malfunction, giving you time to repair or replace the seal.

Corrosion

Not only are mechanical seals safer, they also cause less damage to the equipment they are attached to. Gland packing will corrode whatever they are plugging as friction grinds down both the packing material and the shaft. Mechanical seals can also be designed to be resistant to highly corrosive materials, which are safety and environmental hazards.

Waste

Not only does gland packing cause a lot of product waste, the packing itself is an environmental issue. Unless you are using biodegradable materials packing, which is often made of plastics and other harmful synthetic materials, every roll of packing will end up in a landfill. Mechanical seals are often made of metal or rubber, which can be more environmentally friendly. As laws on use of short term plastic usage increase, – some areas even banning plastic bags – it’s important to stay ahead of the curve so that new systems aren’t implemented in a rush; especially with a device like mechanical seals, which save money in the long run.

Efficiency

Product and equipment efficiency is a good start, but mechanical seals also provide another efficiency incentive. Mechanical seals also reduce energy usage, saving money and the environment. The reduced friction on moving parts when using mechanical seals provides a more fluid range of motion; machines don’t have to work as hard as when they are grinding against packing. This can lead to huge savings and prevent excess consumption of energy.

Design and Installation

All of the aforementioned benefits of mechanical seals hold up only if they are properly designed for the job and installed correctly. To ensure you are getting the right seal for the job, or to create a custom solution for a unique problem, contact Real Seal. They have experts with years of experience in coming up with unique manufacturing solution, providing environmentally sound guidance and ensuring a safe and efficient system.

Which Seal is Ideal for Your Industry Needs?

When it comes to sealing your manufacturing equipment it’s imperative that you choose the right seal made of the correct material. The wrong seal can break, causing loss of product and time. Things can go even worse with unintended chemical reactions and contamination. It’s impossible to be sure unless you consult an expert, but here are a few examples of seals and their applications.

Static Seals

Static seals refer to seals which are placed between surfaces with no relative motion. These seals are perhaps the easiest to maintain and select because of the lack of friction. What need to be taken into consideration are the types of forces being exerted upon the seal. Temperature, chemical makeup, and pressure are the primary concerns when dealing with static seals.

Dynamic Seals

On the other hand, dynamic seals operate between two moving surfaces. Dynamic seals are defined as being reciprocating, rotary, or oscillating depending on the type of motion they are being used between. All of the considerations of static seals are taken in when considering which dynamic seal to use, with the addition of being able to withstand the friction from the specific type of motion against the seal.

Materials and Their Uses

Now that you know which type of seal you need, the specific material becomes the important question. Each material has its uses and more are being developed regularly to take into account new factors such as environmental regulations. Here are a few types of materials and their properties:

Ethylene Propylene Diene Monomer or EPDM is resistant to weathering, ozone, water, and steam. Some of the common uses for EPDM include systems that involve: brake fluids, alcohols, ketones, diluted acids and bases, as well as phosphate ester fluids. Compounds cured with peroxide have excellent compression set resistance.

Acrylonitrile-Butadiene or NBR is the most commonly used material in rubber seals. NBR has amazing resistance to hydrocarbon fluids, cold water, di-ester lubricants, and ethylene glycol fluids. The standard service temperature range is -55 to 250 degrees fahrenheit, but it’s possible to extend this range with specialty compounds.

Hydrogenated Acrylonitrile-Butadiene or HNBR is a version of the above nitrile rubber that has most or all of its double bonds saturated with hydrogen, providing greater heat resistance and chemical resistance.

Carboxylated Acrylonitrile-Butadiene or XNBR is another nitrile rubber that has been altered to improve certain attributes. This variant is best for applications that require greater tensile strength, modulus, and resistance to abrasion, good for dynamic seals and abrasive products.

Silicone Rubber has the broadest temperature range of standard elastomers with a range of -175 to 500 degrees fahrenheit depending on the composition. There is a trade off, though. Silicone products tend to have lower physical strengths compared to carbon elastomers. So, if your manufacturing needs are at extreme temperature, silicon tends to be a better choice.

Polyurethane rubber has the best physical strength and toughness of the elastomeric materials with still impressive temperature ranges from -65 to 300 degrees fahrenheit. This material is resistant to petroleum oils, fuels, oxygen, and ozone, but weak to acids, ketones, and water vapor.

Fluorocarbon Rubber or FKM is best for applications requiring both chemical and heat resistance, reaching up to 400F. These materials are good for use with petroleum oils, diester lubricants, silicate ester lubricants, silicone fluids, acids and bases, and more. There are even FDA grades available for food and beverage applications.

There are many more available options and this is only a brief overview.

Choosing the Right Seal

Choosing the right seal can be difficult. There are so many factors to consider based on each individual application. That’s why it’s best to have an expert source for your materials. Real Seal is an expert in all kinds of seals and will work with you to make sure you choose the right product. If you have unique challenges, new and custom compounds can be engineered to suit your needs. Contact Real Seal today to consult the seal experts.

What is Injection Molding?

Injection molding is process by which sealing devices and components are produced. A whole range of materials can be used in injection molding, from metal to plastic, and even glass. Injection molding allows for a consistent product, but it is imperative that the initial mold design is perfectly suited for the product’s needs.

How it Works

Not all injection molding systems are the same, but there are some procedures that are general to the injection molding process. The material for the component is heated until it is melted and then forced into the mold cavity. Once in the cavity, the material is allowed to cool and harden, maintaining the shape of the mold, creating the desired product. To account for shrinkage, holding pressure must be kept at proper levels. Coolant is also important in certain molding processes, allowing the material to cool at the correct rate.

What it’s Used For

Injection molding is one of the most common manufacturing methods for plastic products, as it creates a uniform product, and is especially useful for mass production of high quantity items. While it’s easy to imagine injection molding being used for small parts such as bottle caps, mechanical components, and electronics; injection molding can be used in large applications as well, such as entire car body panels. Chances are any plastic parts that make up the things you own were injection molded.

Molds

Perhaps the most complex and important part of the molding process are the molds themselves. Molds can be made from a range of materials, usually determined by the economics and requirements of the part being made, including hardened steel, pre-hardened steel, aluminum, and other alloys. Molds are typically expensive to design and make, as they are highly specialized and require extreme precision. The number and complexity of cavities in the mold will determine the cost of the mold, and it’s best to eliminate excess material as this can negatively impact production cost.

Molds are typically made of two plates with indentations and raised areas shaping the desired product. In order for the molten material to travel through the mold, there are “runner” channels through which the liquid flows. Some molds, for smaller parts, are designed in such a way that a single injection of material can yield several parts, making for a more efficient process. These molds can be made to create different or identical parts, so one mold can either perform the same job multiple times or produce a variety of related products in one “shot.”

Any defects in the mold will cause issues with the end product. If the mold is incorrectly sized then the material will warp, blister, or stick to the mold when it has finished the cooling process.

Real Seal’s Molds

Real Seal is an expert in injection molding, offering a wide range of materials for use in state of the art molds. Computer controlled mechanization and consistency ensure a superior product. They have created products ranging from 0.05” to 27” in diameter and have maintained customer tooling for two decades in many cases. If you require custom tooling, Real Seal provides this service on site, typically using insert style retrofitting into established basis, lowering your costs. Since these steps are all done by Real Seal, you can be assured of their consistency and conformity. Contact Real Seal for all your manufacturing needs.

Mechanical Seals vs. Packing: Which is Superior?

As it becomes required and more important to keep manufacturing eco-friendly, the debate between traditional packing versus mechanical seals has become clear. While packing has lower upfront costs, over time it becomes much more expensive as the material requires continual maintenance and replacement. Packing is also more prone to leaking and product loss.

There’s no way around it, pumps need to be sealed. Over time a leaking system can be costly, inefficient, and detrimental to the environment, so it’s imperative to choose the right long-term solution.

How Packing Works

Packing is a relatively simple process. A soft material is stuffed into the gap between the pump and the shaft, preventing most leakage. There are a wide variety of materials used depending on the kind of material being pumped. It’s simple and easy to maintain, which is an advantage for packing.

Disadvantages of Packing

The primary downside of packing is that there is inevitable leakage, which causes a range of issues. The first issue is that leaking fluid can be a working hazard, causing slips and falls and their inevitable workers compensation cases. Many fluids aren’t allowed any visible leakage at all due to the fact they are corrosive, toxic, flammable, or dangerous to the environment. Packing can also cause wear and tear on the machinery they are sealing, causing the machines themselves to require repair or replacement.

Finally, while packing may be cheaper up front, they do lose product due to the leakage, costing money. So, while you may want to start out using packing as a cheaper start-up cost, eventually the packing will become more expensive. Plus, the regular maintenance requirements will eat up time as well, which is yet another cost.

How Mechanical Seals Work

Mechanical seals come in a variety of shapes and sizes, due to the specific nature of their designs and the systems they are used in. Some can be simple, while others are more complex, requiring multiple fail-safes and self-correcting features.

Most basic mechanical seals have three sealing points. The first portion is sealed to the stationary part of the pump with an O-ring. One portion of the seal is generally spring loaded in order to compensate for any minor staff deflection.

Perhaps the most important and complex part of the seal is the middle portion where the rotating and stationary portions meet. This section must be lubricated enough to rotate, but tight enough not to allow any leakage. Both the force of the fluid and the design of the seal contribute to pushing the seal faces together. These surfaces are microscopically flat, ensuring a tight seal so that fluid cannot escape and contaminants won’t enter or damage the seal.

Advantages of Mechanical Seals

Over time, mechanical seals will save you money through a variety of means. Mechanical seals that are correctly chosen, operated, and installed won’t do much damage to the systems they are attached to. They save time as they require little upkeep and maintenance in comparison to packing. Preventing virtually all leakage will prevent money lost through the steady leakage of packing. Mechanical seals also consume less power.

There are disadvantages to mechanical seals, such as a higher initial cost. Mechanical seals are also more difficult to maintain, requiring a higher level of expertise. Most of the disadvantages can be remedied by design decisions, such as creating a secondary seal in case of a failure in the first seal.

Your Needs

No matter your manufacturing needs, Real Seal can provide you with quality solutions for any operation. Contact Real Seal for all of your sealing needs.