ASME B73.3-2003 pdf – Specification for Sealless Horizontal End Suction Metallic Centrifugal Pumps for Chemical Process
ASME B73.3-2003 pdf – Specification for Sealless Horizontal End Suction Metallic Centrifugal Pumps for Chemical Process.
4.6.2 Secondary Control or Secondary Containment.
It will be desirable in some installations to have a backup to control or contain the pumpage in the event that the primary pressure containment (containment shell of MDP or liner of CMP) should rupture. There are two basic methods for this secondary protection.
One method is to provide structure surrounding the primary pressure containment that would confine liquid release through the primary pressure containment but not completely contain it. Some leakage would be permitted through the secondary structure but a rapid release of liquid would be prevented. This method is called Secondary Control.
A second method is to provide structure surrounding the primary pressure containment that would fully contain all liquid released through the primary pressure containment. No leakage is permitted through the secondary structure. This method is called Secondary Containment.
In the event of leakage through the primary pressure containment, for either of the methods above, operation of the pump shall be immediately discontinued.
The purchaser shall be responsible for providing shutdown devices and procedures required for safety.
When specified, one of the following designs to control any leakage from the containment shell or the liner of the primary pressure containment shall be provided by the manufacturer.
126.96.36.199 Secondary Control
(a) Any leakage through the primary containment shall be minimized and safely directed by a boundary made up of devices, including a secondary pressure casing capable of maximum design pressure.
(b) The secondary control shall be drainable to a residual of a maximum of 2 cu. in. (30 ml) or to a value agreed upon by the user and the manufacturer.
(c) The secondary control shall be provided with flush and drain connections.
188.8.131.52 Secondary Containment
(a) Any leakage through the primary containment shall be contained by secondary containment at the maximum allowable working pressure for a minimum of 48 hr.
(b) The secondary containment shall be drainable to a residual of a maximum of 2 cu. in. (30 ml) or to a value agreed upon by the user and the manufacturer.
(c) The secondary containment shall be provided with flush and drain connections.
184.108.40.206.1 Secondary Containment Verification. When specified, a means for periodically checking the secondary containment, for sealing capability, shall be provided by the manufacturer.
4.6.3 Draining. All pumped fluid-containing areas, including vendor-supplied piping, shall be drainable to a residual of a maximum of 2 cu. in. (30 ml), or to a value agreed upon by the manufacturer and purchaser, and shall be suitable for flushing before disassembly.
4.6.4 Monitoring. Provision shall be available to allow for instrumentation to monitor containment shell temperature of magnetic drive pumps.
4.7 External Bearings (MDP)
4.7.1 Bearing Design. Two antifriction bearing assemblies shall be provided. The bearing assemblies shall be designed to withstand radial and axial thrust within the pump design region of para. 220.127.116.11.
4.7.2 Bearing Life. Bearings shall be selected in accordance with ANSI/ABMA-9, ANSI/ABMA-li, and ISO 281/1. The minimum L’loh bearing life shall be 17,500 hr for all standard and optional arrangements of bearings, lubrication, shafts, covers, and sealing.
4.7.3 Sealing. The frame shall be constructed to protect the bearings from water, dust, and other contaminants.
4.7.4 Lubrication. Lubrication may be oil or grease. When oil lubrication is supplied, the frame shall be provided with a level indicator which is capable of optionally being installed on either or both sides of the frame. A constant level oil feed regulator shall also be available, and when provided, be set initially by the manufacturer for the proper level during operation. The proper oil level shall be indicated on the outside of the frame. Other methods of lubrication may be specified, and when provided, the necessary additional taps shall be provided.