Figure 1-The Space Capsule of NASA’s famous "Friendship 7" Mission which made John Glenn the first American astronaut to orbit the Earth
We all know that even the small things impact a lot in our everyday lives & today in this article I will be sharing an interesting story of an unsung clamp who not only participated in NASA’s Space mission but was also responsible for ending WWII. Today I will be discussing the “V-Band Clamp” which has shown its versatility from Deep space missions to countless automotive applications.
1. The History First-
Let’s start by giving the credit to the Inventor Mr. Herbert Manfred "Zeppo" Marx (February 25, 1901 – November 30, 1979) who was an engineer and an American comedic actor who was well known for his outstanding performance in the Marx Brothers feature films. Later he started Marman Products Inc. in 1930 which started manufacturing these V-band clamps (Marman Clamps).
This humble V-Band clamp has played a pivotal role in history having been used by the U.S Military to hold the atomic bombs aboard the “Enola Gay” bomber aircraft as it travelled to Japan for ending World War II and also for clamping the booster rockets on the John Glen’s “Friendship 7” spacecraft as it launched to orbit the earth.
Figure 2-Enola Gay, the B-29bomber that was used by the United States on August 6, 1945, to drop an atomic bomb on Hiroshima, Japan.
2. What are V-band Clamps & How do they work?
V-band clamps are a fastening element that is an easy way of establishing a joint between a pair of circular flanges for pipes, tubes, ducts, pipelines, turbocharger housings, and many more applications. They consist of V-petal segments which sit on the pipe flanges & clamp them securely by generating an axial force to create a leak-free joint. The major parts of the clamp are the Band, V-Petals, T-housing (Trunnion), T-bolt & the Nut.
This clamp works on the Basic principle of an Inclined plane wherein a Mechanical advantage is obtained by means of a wedging action. Once the clamp is mounted on the flanges to be connected, upon inducing an application torque to the nut a Band Tension is generated into the clamp band which generates a Radial load on the V-Petal. This Radial force is then converted to Axial force due to wedging action of the inclined surfaces which creates a leak-free joint.
Figure 3 The working principle of V-band clamps
3. Now forget those old Flanged joints-
Now forget those old school bolted flanged joints, V-band clamps now come with amazing benefits to serve their end users.
When compared to 2 or 3-bolted flanges, the V-band clamps are lighter & occupy very less space in the tight regions of engine bays.
V-band clamps are super quick for installation & removal, they don’t carry the fuss of bolted joints like bolts & nuts, gaskets, glue, etc.
Also, the person removing or reinstalling the bolted joints has to use both hands to prevent any ‘free spinning’ of the Bolts whereas in the case of V-band clamps the operator is supposed to tight only one nut that too at any location due to the circular nature of the V-Band Clamp to access the easiest tightening position.
Apart from this, the V-band clamp applies uniform force around the flange which maximizes the seal potential of the flanges which is not possible in the case of bolted flanged joints.
Altogether V-band clamps are economical when you consider the cost of time in installation and reassembly.
4. The Design in Detail-
Though the working principle of V-clamps seems to be simple, developing & proving the clamp checks the nerves of our Design & Development team. The process goes in a series of events such as Product feasibility, Design, Prototyping & Testing & Validation. Meticulous details affecting clamps performance such as Flange dimensions, Material, Operating temperature & pressure, Working environment, Application area & Type of external loading if any among others are given due consideration while designing the clamp. After the detailed design & prototyping, the developed samples are put through a series of brutal validation tests at our in-house product testing & validation lab. Some of the tests we perform are-
V-band clamp burst pressure test
Pulsating pressure endurance test
Leakage rate test
Axial force measurement test
Validation tests for external loading (Axial, Bending & Torsional loads)
Salt spray test
5. Variety of Configurations-
Here at Jolly clamps, we serve our customers with the highest degree of customizable V-band clamps. The major configurations include-
Worm drive clamp with V-petals- For medium-duty applications with space constraints.
V-profile clamp- For small diameter flange clamping applications
And many more...
All the above styles can be configured in a wide range of material combinations to suit your specific needs. Please contact our Technical Sales Executive for the best clamping solutions today.
6. A Multifaceted Clamp-
Owning the numerous advantages this clamp carries such as ease in assembly, lightweight design, Strong axial forces for sealing against gas, liquid pressure & Low cost among others make this clamp stand apart. Having a Multifaceted personality this clamp is widely used in the following applications-
Securing the exhaust system to the engine manifold
To assemble gas turbine compressors, burners, exhaust ducts, pumps, Muffler assemblies, Turbochargers, etc.
DPF Clamps a type of V-band clamp are designed to make cleaning of diesel particulate filters easier in diesel engines
Used in paper pulp machines & waste oil separators machines
Ensure that the system pressure is released before unfastening the V-band clamp.
While installing the clamp, preload the clamp with 50-70% of the application torque & then tap lightly the clamp periphery with a soft-faced mallet to ensure proper seating of V-petal on the flanges & then deliver the remaining application torque.
Using power tools for the assembly of V-band clamps is not recommended. However, if using a powered device to install the locknut, do not exceed a speed of 120rpm.
More torque is not better & can cause clamp petal permanent deformation which may shorten the clamp's service life.
After installing the clamp check for the V-band clamp's apex gap and foot clearances. At full torque, a positive gap must be maintained throughout to prevent the clamp from bottoming out on the flanges before the required torque has been achieved.