Valve Alignment

A precise valve alignment can be the difference between a good instrument and a great one. Misaligned valves can slow an instruments response, cause an unevenness of timbre and create variable resistance for each of the valve combinations. A Precision Valve Alignment™ (PVA™)  corrects the alignment of the valve on both the upstroke and the downstroke, to within +/- .001". When the valves are lined up properly, the player does not need to compensate for the inefficiencies of the instrument, which means greater ease of control and playability.

To illustrate how critical an accurate valve alignment is, consider the effect of even small changes along the bore of an instrument. For example, opening the throat of a mouthpiece one size is a change of approximately .002", and playing a medium large bore (.459") trumpet as opposed to a large bore (.462") trumpet is a difference of only .003". Valves, however may be misaligned by as much as .015" to .080"! Considering that each valve has six ports, three valves combined provide eighteen possibilities for significant misalignment, which has a tremendous effect on the playability of the instrument.

Valve Alignment Factors

Valve alignment is dependent on many factors, including the construction of the valve assembly and the materials used in aligning the valves.

Each valve assembly consist of the finger button, top cap, valve stem, spring barrel (top of valve), valve guide, and the valve/piston body itself.  Alignment depends in part on the accuracy of the manufacturing of these components:  when any one of these parts is not made to the exact dimensions required, both the up and down positions will be misaligned.  Additionally, the ports on the valve body may be incorrectly spaced, or the horizontal (or rotational, side-to-side) alignment may be off, affecting the alignment.     

Another factor in Precision Valve Alignment™  is the choice of bumper materials.  Felt and rubber are commonly used, yet each one has its problems.  Rubber bumper materials used in adjusting valves work well because the rubber is stable and resist compression.  The thickness of rubber is consistent, but if the valve assembly mentioned above is made incorrectly, the misalignment occurs.

Unlike rubber, felt is generally unstable.  The thickness of a single batch of felt straight from the manufacturer can vary up to .030": when used in adjusting valves, this variance can seriously affect their alignment.  Additionally, over time felt washers will compress with constant use, moisture, and oil.  As the thickness of the felts change, the valves slowly become misaligned, forcing the player to adjust to the ever changing valve alignment.

Types of Valve Alignments

There are basically four kinds of valve alignments being done today.  The first three methods mentioned below incorporate the use of felt to align the valves.

The first  method could be called the standard "factory valve alignment."  In this case, the valve stem felts and top cap bumpers from the instrument's manufacturer are installed, theoretically bringing the instrument back into factory specifications for valve alignment.  While this is a good enough to allow the instrument to play,  it is not accurate nor is it the best way to align valves.

A second method is to align the up- and down-stroke positions of the valves separately. A gauge is used to measure the upstroke position:  from these measurements, it is possible to determine the necessary thickness of cork or felt which will bring the valve into alignment in the up position.  For the downstroke position, the tuning slides are removed, and the valve aligned by sight.  There are two problems with this method.  First the gauge does not take into account the full measurement needed to align the valve in the up position.  Second, aligning the downstroke by sight presents the problem of not being able to see all the valve ports to check the alignment completely.

A third type of alignment is done completely by sight.  Using a mirror to view the valve ports is much more accurate and eliminates any guessing about the valve position.  However, it is not possible to align a valve by sight to +/- .001", nor is it possible to see all the ports necessary for accurate completion of this procedure.

The Precision Valve Alignment™ (PVA™)  is the most accurate method for aligning valves. Using a precision gauge made specifically for this procedure, precise measurements are made of each valve and valve casing port, from which the up-and down-stroke positions of each valve is calculated.  A fiber optic scope is used to view valve port alignments that are not normally visible. Horizontal (or rotational, or side-to-side) alignment is also examined and corrected as needed.

The most important part of a PVA™ , however, is the material that is used to correct the valve alignment. Instead of relying on felt, a special synthetic pad has been developed, which is unaffected by compression, moisture, and oil.  Using the extremely stable synthetic pad insures the precise valve alignment will endure for many years before any replacement is required.

The Results

As a result of a Precision Valve Alignment™ , a musician can expect to experience faster response from the instrument, greater evenness of timbre and resistance throughout the range of the instrument, and greater efficiency of sound production.  With the instrument thus finally tuned, the player can produce a full sound with much less effort, while technique can be improved because of the quickened response from note to note. Instead of being an obstacle, the instrument can now assist the player in creating music.

Customer Appraisal of Precision Valve Alignment™

"To say that I am happy with the results would be an understatement!  I've never had a horn that has played better!   The differences with the brass guides, the alignment and the cryogenic process are amazing.  I have found better "slots" (especially above "Double C") !!  From now on all my horns are coming to the Brass Bow for treatment."

Jon Faddis-Recording Artist

Precision Valve Alignment™ Price List

Note: Price will vary depending on amount of work needed to align each set of valves.  Additional charged required to correct lateral (side-to-side) alignment.  We require your instrument to be clean and have your valve in good condition. We can provide these services for you at additional cost or you can have your local trusted repair shop take care of this for you.