What Makes a “Pump Shaft Quality” Stainless Steel Bar?
Pump shafts are stainless steel bars that can vary in shape depending on the pump application. These bars, however, are manufactured to a higher standard than common steel bars. Elevated requirements come from a variety of factors:
- Vibration – When a shaft is spinning, particularly at higher speeds, vibration within the pumping equipment becomes a concern. Shafts that do not conform to a high degree of straightness can begin to vibrate at higher speeds, potentially causing damage to machinery. As a result, pump shaft quality (PSQ) stainless steel requires very high degrees of straightness. Variances cannot exceed 0.0005” in the first three feet of shaft, and 0.0015” for each foot over the first three. This specification helps eliminate or minimize potentially harmful vibrations within the shaft and equipment.
- Strength – Pump shafts can experience a great deal of heavy use in many applications. Heavy loads and high speeds can put enormous stress on the material, and accidents during transportation of the shaft can place unexpected force on the products. Because of the forces exerted on pump shafts, exacting specifications are required. Pump shaft quality bars have a minimum yield of 75 KSI, and a tensile strength of 100 KSI. This strength allows the bars to withstand heavier loads than regular stainless steel bars.
- Diameter – Outer diameter tolerances for PSQ bars are highly precise due to the nature of the bars. A shaft must perfectly fit the machinery for which it was designed in order to prevent damage to both the machinery and the shaft itself. With outer diameter requirements being critical, all PSQ shafts have the following tolerances:
|Less than 1” outer diameter –||+0” ; -0.002”|
|1.0” to 1.437” outer diameter –||+0” ; -0.0025”|
|1.5” to 4.0” outer diameter –||+0 ; -0.003”|
- Shipping – Because of the critical nature of pump shafts, they must be protected from rough handling during shipping. Cardboard tubing, wooden boxes and other types of packaging are used to protect the bars from becoming damaged during their journey from fabrication to final application. This protection allows customers the comfort of knowing their pump shaft will arrive in the same condition that it left the manufacturer.
Pump shafts have the same qualities of stainless steel, including corrosion resistance. This makes them ideal for applications in which they are exposed to harsh environments.
Elemental conditions experienced in outdoor use can wear down other types of metal and exposure to harsh chemicals can also cause corrosion and damage. The properties of stainless steel will resist corrosion and provide pump shafts with a longer life expectancy, resulting in fewer maintenance costs and delays.
Continental Steel & Tube offers the following grades for use in pump shaft quality bars:
- 17-4 PH
- SS 316
- SS 410
- SS 416
- Alloy 20
- 2205 Duplex
- K500 Monel
Additionally, PSQ steel bars can be manufactured in a range of sizes and shapes to meet the needs of non-standard applications.
This customization ensures that all customers can receive the pump shaft quality stainless steel bars that they require for even the harshest levels of use.