Tech Tips

Achieving the Correct Electrical Conductivity When Welding Copper

welding image

When welding copper in a high electrical conductivity situation, it’s best to know the physical and chemical properties so you know what’s needed in a welding alloy.

Nitrogen Purge and Brazing

Harris nitrogen regulator (part no. 3002572)

Most HVAC installation instructions require flowing nitrogen through the copper tube during brazing. This is an important step in producing a quality HVAC system.

Actual and Typical Certifications

Harris brazing rod

Harris provides online actual and typical certifications for many of our consumable products. This brief overview looks at the difference between the two types of certifications.

Decomposition Arrestors

Harris 220 Switchover Manifold

Because acetylene is a highly flammable and relatively unstable compound when in its pure gaseous form, manifold systems for acetylene are required to have decomposition arrestors installed at each cylinder connection. Both CGA and NFPA mandate this to insure safe handling of the gas as it is withdrawn from the cylinder.

Carbon Dioxide Regulator Freezing

CO2 Freeze Up

Carbon Dioxide gas can, under certain conditions of temperature and pressure, freeze-up and form a solid (dry ice). If this condition occurs the required carbon dioxide gas flow can be restricted or blocked entirely.

What Pressure Range to Choose

Harris regulator

Selecting the proper delivery pressure range of a gas regulator is critical to choosing the right regulator for a particular application.

Soldering New Composition Low Lead Valves

Harris soldering tips

The Reduction of Lead in Drinking Water Act was enacted in 2011 to amend the current Safe Drinking Water Act. New requirements became effective 1/4/14 and included was a provision to further reduce the maximum lead content of wetted surfaces of plumbing products. To comply many valve manufacturers developed different low lead alloy compositions.

Brazing Today's Air Conditioners

Harris brazing with Dynaflow®

As CFC refrigerants are phased out, there has been much discussion about braze joint requirements for the new replacement blends. In either case, one thing hasn't changed. The key to producing leak-proof brazed connections is proper technique. This article discusses key procedures that need to be followed to ensure sound brazed joints.

Solutions for Regulator Mounting Problems

Harris SG 910 BR regulator mount

Mounting a regulator directly to a cylinder is the easiest and most common type of installation, but it isn’t always ideal. You can save yourself a lot of time and money by not having to remove regulators, depressurize the system, change the cylinder, and re-pressurize.

It’s All About Pressure

Harris pipeline regulator

When selecting a pressure regulator for your application, there are a number of things to consider.

Oxy-Fuel Cutting - Choosing The Right Tips

Harris torch cutting scrap

Most users of oxy-fuel cutting torches give little thought to the size of their cutting tips. Scrappers think bigger is better and high end production workers are more concerned with gas consumption costs rather than choosing the right tip for the job. Here are some things to consider when selecting cutting tips.

Stay Silv® Brazing Flux Removal

Brazing with Harris flux

Proper fluxing is important when brazing because the flux absorbs oxides formed during heating and promotes the flow of filler metal. Flux residue must be removed after brazing for inspection of the joint and pressure testing. This article discusses some important tips for proper cleaning of flux residue.

Adjustable Gas Blenders

Harris Gas Blender

Adjustable gas blenders can be used in a wide array of applications including welding processes, pacakaging and food service. These gas blenders are designed to create a custom gas mixture defined by the user with the turn of a single knob. Here are answers to some common questions about adjustable gas blenders.

Gas Delivery Systems

Harris gas distribution system

When gases are used in significant volumes, a centralized gas delivery system is a practical necessity. A well-conceived delivery system will reduce operating costs, increase productivity and enhance safety.

Beveling Plate Edges Prior to Welding

Machine beveling with a Haris BV-98-2 beveling head

The beveling of plate edges before welding is a necessity in many applications both to insure proper dimensions and fit and to allow proper welding techniques to be employed.

Oxy-fuel Equipment Safety Guidelines

Harris Model 25GX regulator

Safety is a full-time responsibility. Accidents don't need to happen. Always follow these basic safety rules when working with oxy-fuel equipment:

Tensile Strength of Brazed Joints

Brazing with Harris alloys

Brazing joint strength depends on several factors: clearance between parts, base metal composition, service temperature and joint quality (low voids, good penetration). Joint design will also affect strength.

Procedures for Soldering

Harris Bridgit® Lead-free Solder

Soldering is a joining process wherein coalescence is produced by heating below 800°F, using a non-ferrous filler metal with a melting point below that of the base metal. This article talks about the proper procedures to follow to ensure a strong soldering joint.

Theory of Oxy-Fuel Gas Cutting

Cutting with a Harris torch

Since the discovery of oxy-acetylene gas cutting by John Harris in 1899, the equipment has been refined and improved but the process itself has remained essentially the same. This article looks at the oxy-fuel cutting process and the theory behind it.

High Silver Alternatives


This Tech Tip comes to us from a customer who has concerns about the cost of high-silver brazing alloys. With the rising silver market, less expensive alternatives are always in demand and we have some recommendations that can reduce cost without sacrificing quality.

Silicon's Role in Blockade

Harris Blockade brazing alloy

Silicon is the second most common element in the earth’s crust, usually in the form of silicon dioxide, (SiO2) or sand. It is an important engineering element used in electronics, abrasives, and metals.

Regulator Flashback Arrestors

Harris Cutting Equipment

Flashback arrestors are commonly used safety devices that stop or impede the progress of a flame front upstream of the insertion point. They are used to prevent damage to equipment, but more importantly to prevent personal injury. This article covers some basic information about regulator flashback arrestors.

Using Flux in HVAC

Brazing with Harris flux and alloy

When brazing copper to brass or to steel a flux is always required. This article discusses tips on proper flux application.

Procedures for Brazing Pipe and Tubing

Harris brazing with Dynaflow®

This article briefly describes the brazing process which is an integral part of manufacturing, installing, and repairing refrigeration and air conditioning systems, and is designed to assist the serviceman or contractor in making sound brazed joints and selecting the correct filler metal for each application.

Controlling Gas Flow

Harris Flowmeter and Flowgauge Regulators

When controlling gas flow, volume is your goal. Choosing the right device in the beginning can sometimes be the difference in your application's success or failure and saving money.

Avoiding Torch and Tip Malfunctions

Railcutting with a Harris torch

Most, if not all serious oxy-fuel torch and tip malfunctions can be traced back to either abuse or misuse of the equipment. Avoid malfunctions by using these tips as a guide.

Troubleshooting Brazing Joints

Harris Brazing

The art of brazing is relatively simple, and the rules are common sense rules. Occasionally, however, things do go wrong, and the brazing process fails to do its job satisfactorily. Here are some tips on what to look for to troubleshoot a brazing joint.

Rivet Cutting and Washing

Harris Cutting and Washing tips

In performing repairs to structures where large metal plates are joined it is often necessary to remove the rivets. This removal can be accomplished in many ways including the use of oxy-fuel equipment. In this instance there are two ways to remove them – rivet cutting and rivet washing.

Oxy-hydrogen Fuel Applications

Harris Tech Tip: Oxy-Hydrogen Fuel Applications

Hydrogen is the most abundant and renewable source of energy available, and is the most important component of any oxy-fuel application. Oxy-hydrogen is a good choice when a flame devoid of contaminants – such as the carbon emitted from the combustion of ordinary hydrocarbon fuels - is needed, but price and safety need to be considered.

NFPA and OSHA Compliant Safety Devices

Harris pipeline flashback arrestors

Flashback arrestors incorporate ASME relief valves and check valves in their design. Unlike hydraulic flash arrestors, dry arrestors are virtually maintenance free.

Silver Brazing Flux

Harris Brazing and Soldering Fluxes

To ensure the best connections, The Harris Products Group produces a wide variety of flux products designed for specific applications throughout a number of different industries.

Rosin and Acid Core Solders

Harris Tech Tips - Rosin core solders

Rosin and acid core solders are manufactured with the solder wire as a tube and the center of the tube contains the flux.

Welding 4130 Chrome-Moly

Harris Tech Tip - Welding 4130

4130 chrome-moly can be welded with the TIG or MIG process.

Working with C02

Harris Tech Tips - Working with CO2

Carbon Dioxide (CO2) gas can, under certain conditions of temperature and pressure, freeze-up and form a solid (dry ice). If this condition occurs the required CO2 gas flow can be restricted or blocked entirely.