enough to bend with this movement or (b) strong enough to withstand the bending moment caused by the movement, without damaging the tub. Thus there is a need for a test that imposes a moment equal to the probable maximum that can be transferred to the fixture by conventional drainfitting assemblies as a result of timber shrinkage or building settlement. The recommended test is based on a consideration of, and data on, these two factors. d. Comments on Performance Requirements (1) Suggested Format for Performance Level The bathtub shall withstand the application of ft-lb of moment or a deflection of. in, as described in paragraph 2.6b (3), without exhibiting surface damage such as cracking, crazing, spalling, lifting of surface coating, etc. The surface damage shall be determined by the inspection procedure prescribed in section 2.8. (2) Rationale for Suggested Format A limit of 50 ft-lb of moment is about the maximum that would be transferred by the presently used assemblies because of their inherent flexibility. A deflection limit of 1.25 in at 30 in (equivalent to 0.5 in at 12 in) would be a conservative one, since (a) the deflection caused by the weight of the lever arm is not measured by this method, and (b) in many buildings, such as reinforced-concrete or steel-framed buildings, or well-constructed buildings framed with dry lumber, the differential movements should be much less than the limit suggested for ths test. On the other hand, some factor of safety is needed to take into account differential movements that can develop in some high-rise systems from thermal expansion of waste and soil stacks. It should be noted that all tubs tested resisted a 50-ft-lb moment without damage and with measured deflections well below 1.25 in at 30 in. The test results suggest that presently manufactured bathtubs are capable of withstanding without damage a moment about the drain outlet equal to or greater than the 50-ft-lb likely to be transferred by the drain-fitting assemblies ordinarily used. 2.7. Watertight-Joint Potential (Bathtub) (S106) No test method exists for determining the watertight-joint potential of bathtubs and no test method is recomemnded. It would seem reasonable that some requirement be made for the water bead along the wall. Federal Specification WW-P-541b (4), 1962 [3] and Commercial Standard CS 77-63 [4] both specify a minimum upturn of water bead of 5/16 in. The minimum upturn found on the tubs investigated in this test program was 3% in. The watertightness of the joint between the floor and the tub apron is dependent upon factors other than bathtub design. These factors are (a) installation and support techniques, (b) differential thermal movements between tub and floor, (c) adhesion, (d) flexibility, and (e) durability of the jointing material. An investigation into design features of bathtubs which would affect the watertight-joint potential was beyond the scope of the present program. However, the recommended tests for Concentrated Load, Sump Sidewall (sec. 2.5), for Concentrated Load (Static) (sec. 2.2), and for Hot-Water Resistance (sec. 2.18) each limit permissible deflections under loading. These limitations should assure indirectly some protection against excessive movement of portions of a bathtub in contact with the wall or with the finished floor when the tub is subjected to loading. These maximum-permissible deflections also provide some guidance on the amount of movement that should be accommodated by joint sealants. 2.8. Surface Inspection (M201) a. Purpose and Scope The purpose of the surface-inspection test is (a) to specify a standard procedure for inspection of a sanitary plumbing fixture for defects and blemishes, and (b) to define the type and number of imperfections that are permissible in a newly manufactured fixture. Although the inspection procedure as specified can be used for all types of sanitary plumbing fixtures, the types and permissible number of defects and blemishes as stated herein apply to bathtubs only. b. Recommended Test Method (1) Inspection Procedure Maintain the temperature of the inspection area and fixture to be inspected at 75 10 °F. Wash the fixture with soap and water and rinse with tap water. After drying, use a sponge to apply an ink solution consisting of 50 percent by volume water-soluble black ink in tap water, or use an ink that contrasts in color if the fixture is colored. Wipe excess ink from surface with a damp cloth and allow fixture to dry. Inspect the surface of the ink-treated fixture visually at a normal reading distance for blemishes and defects. Use a light source of partially diffused daylight or substantially equivalent artificial light, with a luminous intensity near the inspection surface of not less than 100 nor greater than 200-ft candles. If surface blemishes or defects are observed to be segregated in a particular area of the fixture, prepare a small cardboard sheet or thinmetal sheet with a circular viewing window three inches in diameter. Use this inspection window to make counts of defects within the area of maximum concentration of defects. (2) Suggested Surface-Finish Requirements The surfaces of the fixtures intended to be visible after installation shall be smooth and free from local variations in color and texture that detract from the appearance of the fixture. Some waviness is typical of certain finishes, and this waviness shall not be a cause for rejection. Other imperfections in the finish that shall or shall not be permissible when fixture is examined as specified in paragraph 2.8b (1) are listed in table 2.8-1. (3) Definitions Blisters-Rounded elevations of the surface that can be penetrated by application of a localized pressure. Cracks-Visible fractures in the finish, usually of a hairline type. Chips-Small damaged areas in the finish, such as those characterized by loss of coating fragments from a localized impact. Dents-Local depressions or raised portions in the surface caused by an impact, or a permanent deformation, in which no fracture occurs. Dimples-Slight depressions in the surface that do not extend to the backing material. Dunts-Hairline fractures extending through the thickness of the fixture. Die marks-Visible scorings in the surface finish caused by improper forming operations. Lumps-Raised portions on a finish, such as those characterized by an accidental application of a blob of coating material during the manufacturing operation. Molding irregularities-Any visible distortion of small size relating to mold imperfections. Pinholes-Small holes in a coating that extend to the backing material. Pores (surface)-Small voids at the surface of the finish. Roping-Shallow ridges and valleys in a finish with no decorative pattern. Spalls Small discontinuities in the surface caused by the loss of fragments after manufacture. These discontinuities may or may not extend to the backing material. In porcelain-enamel coatings, spalls of this type are often referred to as fish scales. Specks-Particles of embedded foreign matter that produce areas of contrasting color on the surface, but not including specks or flecks purposely incorporated into a finish to produce a decorative pattern. Wrinkles-Corrugations in the finish that can be seen or felt and which follow no fixed pattern. (4) Information to be Reported Include the following in the test report: 1. Identification of fixture; 2. A qualitative description of color uniformity; 3. A qualitative statement on uniformity of texture; 4. A statement as to the presence or absence of each surface imperfection listed in table 2.8-1 together with the size and number of each, when present; 5. A statement as to whether the fixture passes or fails the surface-finish-requirements specified in paragraph 2.8b (2). c. Test Results and Discussion (1) Discussion of Test Development Surface-finish requirements as incorporated into Commercial Standards and into Federal Specifications were reviewed for each material that is being used for sanitary plumbing fixtures. All of these requirements were quite similar. This permitted their consolidation into a single surface inspection test. The consolidation was done in such a way that any currently produced bathtub fixture that now passes its own commercial standard for surface inspection will also pass the requirements set forth in section 2.8(b). No laboratory investigations were either possible or were they needed in the development of this particular test. However, numerous inspections of fixtures furnished for test were made using the specified test procedures. All the fixtures inspected passed the requirements of section 2.8(b). d. Comments on Performance Requirements (1) Suggested Format for a Performance Level Surfaces of the fixture intended to be visible after installation shall meet the requirements for finish quality listed in paragraph 2.8b (2) and in table 2.8.1. (2) Rationale for Suggested Format Since new fixtures that pass the requirements for surface finish specified in the commercial standards are apparently acceptable to the general public, there would seem to be no legitimate reason for increasing the surface-finish requirements from their present levels. In effect, the suggested format as given above would insure that the present quality levels are maintained. 2.9. Water Absorption (M202) A water absorption test for sanitary plumbing fixture materials might serve as a control test for some material. The amount of water absorbed might also bear some relation to performance of given materials when subjected to other tests. No test is recommended for water absorption at this time, because (1) existing tests for water absorption do not closely simulate service exposure, and (2) certain other tests recommended in this report probably provide adequate protection against any important effects attributable to water absorption that may occur in a service environ ment. A test method for water absorption of FRPE sanitary ware is specified in section 6.2 of the proposed revision of CS 221-59 [1]. This involves total immersion of specimens cut from an FRPE bathtub in water at 23 °C for 24 hr. according to the procedure of paragraphs 6(a) of ASTM D570– 63 [5]. Water absorption is required not to exceed 0.50 percent by weight. Other test methods for water absorption of sanitary ware are described in standards [3,6,7]. These involve total exposure of broken specimens to boiling water, after which the absorption is required not to exceed specified percentages by weight. These tests are not considered to be an adequate simulation of typical exposure of a bathtub to water under normal use conditions. Among the deficiencies of these tests as performance tests to evaluate the water-absorption effect on sanitary ware are the following: 1. Some of the tests involve the unrepresentative exposure of both surfaces and cut or broken edges of a specimen to water at unrealistically high temperature. Furthermore, different materials with suitable service records are known to absorb widely varying amounts of water in immersion tests of cut or broken specimens. 2. For the kinds of materials used for bathtubs, failure caused by water absorption is more likely to result from flaws or defects that are widely separated rather than from effects of uniform penetration of water. The exposure of small flat specimens cut from the fixture may not reveal tendencies to defects that sometimes occur at the fillets or curved areas between the bottom and sidewalls. 3. The existing test methods for water absorption are considered useful essentially as control tests for materials on which some service experience on performance has been accumulated; hence, without modifications, they probably would have limited value for new materials even as control tests. Several of the tests recommended herein are believed to provide the needed protection against possible deleterious effects of water absorption through the finished surfaces of sanitary ware. These are given in section 2.18 (hot-water resistance), sec. 2.10 (abrasion resistance), section 2.12 (surface-impact resistance), and section 2.16 (scratch resistance). However, it is emphasized here that no correlation between test results and service performance has been attempted with respect to water absorption per se, nor were any measurements of water absorption made in developing the recommended tests. 2.10. Abrasion Resistance (M203) a. Purpose and Scope The purpose of this test is to evaluate resistance of sanitary plumbing fixtures to the type of abrasion that occurs in normal use. b. Recommended Test Method (1) Apparatus The apparatus for abrading specimens shall be the Gardner Heavy Duty Wear Tester," shown in figure 2.10-1. This apparatus as used herein abrades specimens by the reciprocating action of four hog-bristle brushes moving back and forth across 12 specimens (three per brush). The specimens are mounted at the same level on a horizontal bed. A water slurry of scouring powder is fed continuously through small holes in the brushes while the equipment is in operation. The brushes, each of which carries a load of 1,100 g, traverse the specimens at a fixed frequency of 120 strokes (60 cycles)/min. The length of the stroke is 13 in. The velocity of travel is constant except during the reversal at the end of each stroke. The feed rate of the slurry through each brush is controlled at 3.0 to 3.5 ml/min. The brushes are mounted in brush holders, provided with fittings for plastic tubing, -in inside diameter. The slurry is contained in a battery jar, 8 in in diameter by 12 in high. Four aluminum tubes extend into the jar and plastic tubing, 1-in inside diameter, is connected to these tubes. The slurry is kept in suspension with a motor-driven stirring apparatus. The slurry is delivered to the four brushes through the plastic tubing by means of a metering pump. The apparatus for measuring abrasive-wear depth shall consist of a dial thickness or depth gage, graduated in 0.001-in increments with a sensor stem (14 in in diam and flat on the end). The gage shall be mounted on a clamp above a flat plate, so that the height above the plate can be adjusted for specimens of varying thickness. Available from Gardner Laboratory, Inc., P.O. Box 5728, Bethesda, Md. 20014. While this test method is described in terms of the Gardner Machine for concreteness, other machines with equal or better performance in all essential respects should be acceptable. mens using the Gardner Heavy Duty Wear Tester following the operating procedure outlined in section 6.5 of the proposed revision of CS 221-59, but using the abrasive slurry specified herein in paragraph 2.10b (2) in place of the Ajax brand powder specified in the proposed revision. The essential features of the test procedure are described below: Dissolve the sodium carboxymethyl cellulose in the water. Next add the trisodium phosphate and ground quartz powder and suspend by stirring. With the power-driven stirrer in operation, adjust the flow rate to 3.0 to 3.5 ml/min. The flow rate can be determined for each setting by measuring the volume delivered in 10 min to a 100 ml graduate. Clamp 12 specimens in the two trays on the horizontal bed of the machine, six to each tray. This provides four rows of three specimens each, comprising one row for each of the four brushes. Use shims as necessary to adjust the specimens and end plates to the same height. If there are less than 12 specimens, use specimens of the same or similar material to fill in the blank spaces. Assemble the scrubbing apparatus, consisting of brushes, holders, and guide plate, and connect the plastic tubing from the slurry jar to the brush holders. Start the pump and determine that the slurry is flowing freely without air bubbles in the tubing. Scrub at a rate of 60 cycles per minute for 10,000 cycles (20,000 strokes) except stop the machine at 2,500, 5,000, and 7,500 cycles to observe specimens, to wash excess slurry from the specimen trays, and to change the brush positions (see table 2.10-1). Also check brush blocks at each inspection period to be certain that the holes are free for the passage of slurry. depth gage to the nearest 0.001 in. In making this measurement, place the specimen on the flat plate and adjust the clamp on which the gage is mounted so that the stem of the gage touches the specimen. Next, move the specimen to a position such that the stem of the gage contacts the approximate center of the wear pattern. Set the zero of the dial gage at the lowest depth that is observed in this area. Finally, move the specimen so that the stem of the gage contacts the unabraded surface. This reading is the abrasive-wear depth for the specimen. The abrasive-wear depth for the fixture is the arithmetic average for the three specimens. (5) Information to be Reported Include the following in the test report: 1. Specimen identification; 2. Cycles required to wear through the coating, in cases where the coating is worn through to the backing material, as shown by change in color and texture; 3. If no wear-through occurs on any of the specimens, report the abrasive-wear depth for each specimen and also the average for the three specimens. c. Test Results and Discussion (1) Discussion of Existing Methods Three test methods for evaluating the abrasion resistance of sanitary plumbing fixtures were investigated. One of these is described in the ASTM test for abrasion resistance of porcelain enamels [8]. The method of abrading specimens consists of placing fixed weights of alloy steel balls, abrasive, and water in a cylindrical container with a rubber ring at the bottom to serve as a gasket. The balls and abrasive rest on the surface of the specimen. The container is clamped to the specimen and the assembly placed on the platform of an oscillating shaker ("RoTap" machine with no tapper). The treatment time is calibrated through use of standard specimens of plate glass. Two types of abrasion are measured. For surface abrasion, the abrasive is the fraction of Pennsylvania glass sand (quartz) passing a No. 70 sieve and retained on a No. 100 sieve. For subsurface abrasion, the abrasive is No. 80 electric corundum. Surface abrasion is measured by changes in 45° specular gloss and subsurface abrasion is measured by changes in weight. Although both surface- and subsurface-abrasion tests by this method have been shown to be reproducible, it has not been shown that this type of abrasive action simulates that which occurs in the normal use of sanitary plumbing fixtures. Abrasion of installed fixtures occurs largely from the use of scouring powder for cleaning. The action of oscillating steel balls moving over an abrasive on the surface of a specimen does not generate the same type of abrasive action as that of a person cleaning the fixture with a commercial scour 21 |