Don’t know thw Texas codes, in Florida it is a trap comming off a waste arm, since the other is a vent.
SECTION 1002 TRAP REQUIREMENTS **
http://ecodes.citation.com/images/NavPara.gif
1002.1 Fixture traps.** Each plumbing fixture shall be separately trapped by a water-seal trap, except as otherwise permitted by this code. The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches (610 mm) and the horizontal distance shall not exceed 30 inches (610 mm) measured from the centerline of the fixture outlet to the centerline of the inlet of the trap. The height of a clothes washer standpipe above a trap shall conform to Section 802.4. A fixture shall not be double trapped. **
Exceptions:**
http://ecodes.citation.com/images/NavPara.gif
- This section shall not apply to fixtures with integral traps.
http://ecodes.citation.com/images/NavPara.gif
- A combination plumbing fixture is permitted to be installed on one trap, provided that one compartment is not more than 6 inches (152 mm) deeper than the other compartment and the waste outlets are not more than 30 inches (762 mm) apart.
http://ecodes.citation.com/images/NavPara.gif
- A grease trap intended to serve as a fixture trap in accordance with the manufacturer’s installation instructions shall be permitted to serve as the trap for a single fixture or a combination sink of not more than three compartments where the vertical distance from the fixture outlet to the inlet of the interceptor does not exceed 30 inches (762 mm) and the developed length of the waste pipe from the most upstream fixture outlet to the inlet of the interceptor does not exceed 60 inches (1524 mm).**
http://ecodes.citation.com/images/NavPara.gif
1002.2 Design of traps.** Fixture traps shall be self-scouring. Fixture traps shall not have interior partitions, except where such traps are integral with the fixture or where such traps are constructed of an approved material that is resistant to corrosion and degradation. Slip joints shall be made with an approved elastomeric gasket and shall be installed only on the trap inlet, trap outlet and within the trap seal. **
http://ecodes.citation.com/images/NavPara.gif
1002.3 Prohibited traps.** The following types of traps are prohibited:
http://ecodes.citation.com/images/NavPara.gif
- Traps that depend on moving parts to maintain the seal.
http://ecodes.citation.com/images/NavPara.gif
- Bell traps.
http://ecodes.citation.com/images/NavPara.gif
- Crown-vented traps.
http://ecodes.citation.com/images/NavPara.gif
- Traps not integral with a fixture and that depend on interior partitions for the seal, except those traps constructed of an approved material that is resistant to corrosion and degradation.
http://ecodes.citation.com/images/NavPara.gif
- “S” traps.
http://ecodes.citation.com/images/NavPara.gif
- Drum traps. **
Exception:** Drum traps used as solids interceptors and drum traps serving chemical waste systems shall not be prohibited.**
http://ecodes.citation.com/images/NavPara.gif
1002.4 Trap seals.** Each fixture trap shall have a liquid seal of not less than 2 inches (51 mm) and not more than 4 inches (102 mm), or deeper for special designs relating to accessible fixtures. Where a trap seal is subject to loss by evaporation, a trap seal primer valve shall be installed. A trap seal primer valve shall conform to [ASSE 1018](javascript:vo() or [ASSE 1044. ](javascript:vo();)**
http://ecodes.citation.com/images/NavPara.gif
1002.5 Size of fixture traps.** Fixture trap size shall be sufficient to drain the fixture rapidly and not less than the size indicated in Table 709.1. A trap shall not be larger than the drainage pipe into which the trap discharges. **
http://ecodes.citation.com/images/NavPara.gif
1002.6 Building traps.** Building (house) traps shall be prohibited, except where local conditions necessitate such traps. Building traps shall be provided with a cleanout and a relief vent or fresh air intake on the inlet side of the trap. The size of the relief vent or fresh air intake shall not be less than one-half the diameter of the drain to which the relief vent or air intake connects. Such relief vent or fresh air intake shall be carried above grade and shall be terminated in a screened outlet located outside the building. **
http://ecodes.citation.com/images/NavPara.gif
1002.7 Trap setting and protection.** Traps shall be set level with respect to the trap seal and, where necessary, shall be protected from freezing. **
http://ecodes.citation.com/images/NavPara.gif
1002.8 Recess for trap connection.** A recess provided for connection of the underground trap, such as one serving a bathtub in slab-type construction, shall have sides and a bottom of corrosion-resistant, insect- and verminproof construction. **
http://ecodes.citation.com/images/NavPara.gif
1002.9 Acid-resisting traps.** Where a vitrified clay or other brittleware, acid-resisting trap is installed underground, such trap shall be embedded in concrete extending 6 inches (152 mm) beyond the bottom and sides of the trap. **
http://ecodes.citation.com/images/NavPara.gif
1002.10 Plumbing in mental health centers.** In mental health centers, pipes and traps shall not be exposed.