Measuring for Success – The Importance of Field Measurements and Test Fits
As an application engineering veteran of 20 years, I have been involved with hundreds of hardware installations on steam systems. Through these experiences, I have learned two important lessons: take comprehensive field measurements and do test fits.
Our steam equipment often interfaces with OEM and non-OEM equipment that has been installed over multiple decades. Additionally, OEM equipment installations vary greatly based on the system engineering firm and installation contractor. Over time, records get lost, designs evolve, and systems are modified. Ensuring new steam equipment fits properly often requires comprehensive field measurements and test fits. To illustrate the importance of this, I share two personal experiences.
Field Measurement Case Study
Early in my career we were installing a rotary joint and syphon system on a paper machine. The project included 50 rotary joints and cantilever syphons. Since the installation was on a newer paper machine, we had up-to-date OEM drawings. I also took field measurements. All 50 sets of steam equipment were shipped to the customer for installation during a shutdown. When the installation crew went to install the cantilever support tube, the tube would not clear the dryer hood. Twenty-eight holes (all top dryers) had to be cut into the dryer hood to fit the tubes. The installation was completed, and the machine started up on time, but the experience left a clear lesson; field measurements must also include the surrounding clearances, not just the mating surfaces. Today, our field service team follows a template for taking field measurements, including clearances.
Test Fit Case Study
In some cases, field measurements are not enough, and a test fit is needed to ensure success. Recently a mill asked us to supply steam sleeves for new dryer cans. The steam sleeve was a packing style design that we had not supplied in years but was required for this style of dryer can. Because of this we wanted to test fit the sleeves into the dryer journal before the dryer cans were installed on the machine. The customer agreed, but thought the check was unnecessary because we had accurate OEM drawings. During the fit, it was found the OEM had not completely bored the dryer can journal and the steam sleeves would not fit. The prints were correct, but the parts were not. The test fit had prevented the issue from being discovered during an installation shutdown. The OEM is boring the journals onsite, and the customer is insisting we come back for a final test fit.
Taking field measurements or conducting test fits requires an expert trained to provide accurate and repeatable results. Kadant Johnson Services takes field measurements as well as conducts test fits before major installations. This includes measuring and checking piping locations, surrounding clearances, bolt hole sizes and threads, and existing equipment dimensions. They are trained, experienced, and their measurements are repeatable. They follow a standard template when taking dimensions that reduces the opportunity for error or missed dimensions. Having the correct information before the manufacture and shipment of steam equipment is inexpensive insurance to ensure a successful installation.