UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

(Address of principal executive offices, including zip code)

(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

PART I. FINANCIAL INFORMATION

Item 1. Financial Statements

The accompanying notes are an integral part of the consolidated financial statements.

The accompanying notes are an integral part of the consolidated financial statements.

The accompanying notes are an integral part of the consolidated financial statements.

The accompanying notes are an integral part of the consolidated financial statements.

The accompanying notes are an integral part of the consolidated financial statements.

1. Description of Business and Basis of Presentation

Description of Business

Westlake Chemical Partners LP (the "Partnership") is a Delaware limited partnership formed in March 2014 to operate, acquire and develop ethylene production facilities and related assets. On August 4, 2014, the Partnership completed its initial public offering (the "IPO") of 12,937,500 common units representing limited partner interests.

Basis of Presentation

The accompanying unaudited consolidated interim financial statements were prepared in accordance with the rules and regulations of the Securities and Exchange Commission (the "SEC") for interim periods. Accordingly, certain information and footnotes required for complete financial statements under generally accepted accounting principles in the United States ("U.S. GAAP") have not been included. These interim consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto of the Partnership included in the annual report on Form 10-K for the fiscal year ended December 31, 2021 (the "2021 Form 10-K"), filed with the SEC on March 2, 2022. These financial statements have been prepared in conformity with the accounting principles and practices as disclosed in the notes to the consolidated financial statements of the Partnership for the fiscal year ended December 31, 2021.

References to "Westlake" refer collectively to Westlake Corporation (formerly known as Westlake Chemical Corporation) and its subsidiaries, other than the Partnership, OpCo and OpCo GP.

The Partnership holds a 22.8% limited partner interest and the entire non-economic general partner interest in OpCo. The remaining 77.2% limited partner interest in OpCo is owned directly by Westlake, which has no rights to direct the activities that most significantly impact the economic performance of OpCo. As a result of the fact that substantially all of OpCo's activities are conducted on behalf of Westlake, and the fact that OpCo exhibits disproportionality of voting rights to economic interest, OpCo was deemed to be a variable interest entity. The Partnership, through its ownership of OpCo's general partner, has the power to direct the activities that most significantly impact the economic performance of OpCo, and it also has the obligation or right to absorb losses or receive benefits from OpCo that could potentially be significant to OpCo. As such, the Partnership was determined to be OpCo's primary beneficiary and therefore consolidates OpCo's results of operations and financial position. Westlake's retained interest of 77.2% is recorded as noncontrolling interest in the Partnership's consolidated financial statements.

In the opinion of the Partnership's management, the accompanying unaudited consolidated interim financial statements reflect all adjustments (consisting only of normal recurring adjustments) that are necessary for a fair statement of the Partnership's financial position as of JuneSeptember 30, 2022, its results of operations for the three and sixnine months ended JuneSeptember 30, 2022 and 2021 and the changes in its cash position for the sixnine months ended JuneSeptember 30, 2022 and 2021.

Results of operations and changes in cash position for the interim periods presented are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2022 or any other interim period. The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities. Actual results could differ materially from those estimates.

2. Accounts Receivable—Third Parties

Accounts receivable—third parties consist of the following:

3. Inventories

Inventories consist of the following:

4. Property, Plant and Equipment

Depreciation expense on property, plant and equipment of $23,888$23,368 and $22,983$23,010 is included in cost of sales in the consolidated statements of operations for the three months ended JuneSeptember 30, 2022 and 2021, respectively. Depreciation expense on property, plant and equipment of $47,884$71,252 and $45,785$68,795 is included in cost of sales in the consolidated statements of operations for the sixnine months ended JuneSeptember 30, 2022 and 2021, respectively.

5. Deferred Charges and Other Assets

Amortization expense on other assets of $7,121$6,023 and $5,719$3,576 is included in cost of sales in the consolidated statements of operations for the three months ended JuneSeptember 30, 2022 and 2021, respectively. Amortization expense on other assets of $14,407$20,430 and $10,459$14,035 is included in cost of sales in the consolidated statements of operations for the sixnine months ended JuneSeptember 30, 2022 and 2021, respectively.

6. Distributions and Net Income Per Limited Partner Unit

On August 1,October 31, 2022, the board of directors of Westlake Chemical Partners GP LLC ("Westlake GP"), the Partnership's general partner, declared a quarterly cash distribution for the three months ended JuneSeptember 30, 2022 of $0.4714 per unit. This distribution is payable on August 25,November 28, 2022 to unitholders of record as of August 11,November 10, 2022.

Distributions are declared subsequent to quarter end; therefore, the table below represents total cash distributions declared from earnings of the related periods pertaining to such distributions.

Net income per unit applicable to common limited partner units is computed by dividing the respective limited partners' interest in net income by the weighted-average number of common units outstanding for the period. Because the Partnership has more than one class of participating securities, it uses the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units and incentive distribution rights. Net income attributable to the Partnership is allocated to the unitholders in accordance with their respective ownership percentages in preparation of the consolidated statements of changes in equity. However, when distributions related to the incentive distribution rights are made, net income equal to the amount of those distributions is first allocated to the general partner before the remaining net income is allocated to the unitholders based on their respective ownership percentages. Basic and diluted net income per unit is the same because the Partnership does not have any potentially dilutive units outstanding for the periods presented.

The amended Partnership Agreement provides that the Partnership will distribute cash that is deemed to be operating surplus each quarter to all the unitholders, pro rata, until each unit has received a distribution of $1.2938. If cash distributions to the Partnership's unitholders exceed $1.2938 per common unit in any quarter, the Partnership's unitholders and Westlake, as the holder of the Partnership's incentive distribution rights, will receive distributions according to the following percentage allocations:

The Partnership's distribution for the three months ended JuneSeptember 30, 2022 did not exceed the $1.2938 per unit threshold, and, as a result, no distribution was made with respect to the Partnership's incentive distribution rights to Westlake, as the holder of the Partnership's incentive distribution rights.

Distribution Per Common Unit

Distributions per common unit for the three and sixnine months ended JuneSeptember 30, 2022 and 2021 were as follows:

On October 4, 2018, the Partnership and Westlake Chemical Partners GP LLC, the general partner of the Partnership, entered into an Equity Distribution Agreement with UBS Securities LLC, Barclays Capital Inc., Citigroup Global Markets Inc., Deutsche Bank Securities Inc., RBC Capital Markets, LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Wells Fargo Securities, LLC to offer and sell the Partnership's common units, from time to time, up to an aggregate offering amount of $50,000. The Equity Distribution Agreement was amended on February 28, 2020 to reference a new shelf registration for utilization under this agreement. No common units were issued under this program as of JuneSeptember 30, 2022.

On March 29, 2019, the Partnership completed the issuance and sale of 2,940,818 common units at a price of $21.40 per unit through a private placement. TTWF LP, Westlake's principal stockholder and a related party, acquired 1,401,869 common units out of 2,940,818 common units issued in the private placement.

The Partnership and OpCo regularly enter into related party transactions with Westlake. See below for a description of transactions with related parties.

Sales to Related Parties

OpCo sells ethylene to Westlake under the Ethylene Sales Agreement. Additionally, the Partnership and OpCo from time to time provide other services or products for which it charges Westlake a fee.

Sales to related parties were as follows:

Cost of Sales from Related Parties

Charges for goods and services purchased by the Partnership and OpCo from Westlake and included in cost of sales relate primarily to feedstock purchased under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement.

Charges from related parties in cost of sales were as follows:

Services from Related Parties Included in Selling, General and Administrative Expenses

Charges for services purchased by the Partnership from Westlake and included in selling, general and administrative expenses primarily relate to services Westlake performs on behalf of the Partnership under the Omnibus Agreement, including the Partnership's finance, legal, information technology, human resources, communication, ethics and compliance and other administrative functions.

Charges from related parties included within selling, general and administrative expenses were as follows:

Goods and Services from Related Parties Capitalized as Assets

Charges for goods and services purchased by the Partnership and OpCo from Westlake which were capitalized as assets relate primarily to the services of Westlake employees under the Services and Secondment Agreement.

Charges from related parties for goods and services capitalized as assets were as follows:

Receivable under the Investment Management Agreement

On August 1, 2017, the Partnership, OpCo and Westlake executed an investment management agreement (the "Investment Management Agreement") that authorized Westlake to invest the Partnership's and OpCo's excess cash with Westlake for a term of up to a maximum of nine months. Per the terms of the Investment Management Agreement, the Partnership earns a market return plus five basis points and Westlake provides daily availability of the invested cash to meet any liquidity needs of the Partnership or OpCo. Accrued interest of $191$691 and $71 was included in the receivable under the Investment Management Agreement balance at JuneSeptember 30, 2022 and December 31, 2021, respectively. Total interest earned related to the Investment Management Agreement was $191$691 and $77$81 for the three months ended JuneSeptember 30, 2022 and 2021, respectively, and $243$934 and $145$225 for the sixnine months ended JuneSeptember 30, 2022 and 2021, respectively.

The Partnership's receivable under the Investment Management Agreement was as follows:

Accounts Receivable from Related Parties

The Partnership's accounts receivable from Westlake result primarily from ethylene sales to Westlake and the buyer deficiency fee and shortfall fee recognized under the Ethylene Sales Agreement.

In 2021, OpCo declared force majeure events relatedThe buyer deficiency fees discussed above under "Sales to Related Parties" recognized in the flash fire atnine months ended September 30, 2022 are scheduled to be received by the Petro 2 facility, OpCo's Petro 1 facility outage, and the severe winter storm. Partnership after December 31, 2022.

As a result of thesethe force majeure events in 2021, the Partnership recognized revenue for a buyer deficiency fee of $51,395 and a shortfall fee of $58,906 during 2021. The buyer deficiency fee was collected from Westlake in January 2022 and the shortfall fee recognized in 2021 is recoverable during 2022 per the Ethylene Sales Agreement.

The Partnership's accounts receivable from Westlake were as follows:

Accounts Payable to Related Parties

The Partnership's accounts payable to Westlake result primarily from feedstock purchases under the Feedstock Supply Agreement and services provided under the Services and Secondment Agreement and the Omnibus Agreement.

The Partnership's accounts payable to Westlake were as follows:

Related Party Leases

OpCo is obligated to Westlake under various long-term and short-term noncancelable operating leases, primarily related to rail car leases and land. Operating lease rentals paid to Westlake for such leases were $574$719 and $608$997 for the three months ended JuneSeptember 30, 2022 and 2021, respectively, and $1,260$1,979 and $1,295$2,292 for the sixnine months ended JuneSeptember 30, 2022 and 2021, respectively, and reflected in other charges from Westlake that are included in cost of sales.

OpCo has 2two site lease agreements with Westlake, each of which has a term of 50 years. Pursuant to the site lease agreements, OpCo pays Westlake one dollar per site per year.

Debt Payable to Related Parties

See Note 9 for a description of related party debt payable balances.

Interest on related party debt payable balances for the three months ended JuneSeptember 30, 2022 and 2021 was $2,859$3,645 and $2,224,$2,190, respectively. Interest on related party debt payable balances for the sixnine months ended JuneSeptember 30, 2022 and 2021 was $5,058$8,703 and $4,460,$6,650, respectively. Interest on related party debt payable is presented as interest expense—Westlake in the consolidated statements of operations. At JuneSeptember 30, 2022 and December 31, 2021, accrued interest on related party debt was $2,997$3,544 and $2,176, respectively, and is reflected as a component of accrued and other liabilities in the consolidated balance sheets.

Debt payable to related parties was as follows:

Major Customer and Concentration of Credit Risk

During the three months ended JuneSeptember 30, 2022 and 2021, Westlake accounted for approximately 81.4%87.8% and 74.8%84.3%, respectively, of the Partnership's net sales. During the sixnine months ended JuneSeptember 30, 2022 and 2021, Westlake accounted for approximately 80.8%83.2% and 78.0%80.1%, respectively, of the Partnership's net sales.

9. Long-Term Debt Payable to Westlake

Long-term debt payable to Westlake consists of the following:

On July 12, 2022, OpCo entered into the Second Amendment (the "OpCo Revolver Amendment") to the Amended and Restated Senior Unsecured Revolving Credit Agreement (as so amended, the "OpCo Revolver"). Prior to the OpCo Revolver Amendment, the OpCo Revolver bore interest at the London Interbank Offered Rate ("LIBOR") plus 2.0%. The OpCo Revolver Amendment, among other things, extended the maturity date of the OpCo Revolver from September 25, 2023 to July 12, 2027 and provided for the replacement of LIBOR with the Secured Overnight Financing Rate, as administered by the Federal Reserve Bank of New York ("SOFR"). Borrowings under the OpCo Revolver now bear interest at a variable rate of either (a) SOFR plus the Applicable Margin plus a 0.10% credit spread adjustment or, if SOFR is no longer available, (b) the Alternate Base Rate plus the Applicable Margin minus 1.0%. The Applicable Margin under the OpCo Revolver is 1.75%. As of September 30, 2022, outstanding borrowings under the OpCo Revolver bore interest at SOFR plus the Applicable Margin and credit spread adjustment.

On July 12, 2022, the Partnership entered into the Fourth Amendment (the "MLP Revolver Amendment") to the Senior Unsecured Revolving Credit Agreement (the "MLP Revolver"). Prior to the MLP Revolver Amendment, the MLP Revolver bore interest at a variable rate of either (a) LIBOR plus 2.0% or, if LIBOR were no longer available, (b) the Alternate Base Rate plus 1.0%. The MLP Revolver Amendment, among other things, extended the maturity date of the MLP Revolver from March 19, 2023 to July 12, 2027 and provided for the replacement of LIBOR with SOFR. Borrowings under the MLP Revolver will now bear interest at a variable rate of either (a) SOFR plus the Applicable Margin plus a 0.10% credit spread adjustment or, if SOFR is no longer available, (b) the Alternate Base Rate plus the Applicable Margin minus 1.0%. The Applicable Margin under the MLP Revolver varies between 1.75% and 2.75%, depending on the Partnership's Consolidated Leverage Ratio. As of September 30, 2022, outstanding borrowings under the MLP Revolver bore interest at SOFR plus the Applicable Margin and credit spread adjustment.

The weighted average interest rate on all debt was 3.0%3.4% and 2.1% at JuneSeptember 30, 2022 and December 31, 2021, respectively.

As of JuneSeptember 30, 2022, the Partnership was in compliance with all of the covenants under the OpCo Revolver and the MLP Revolver.

10. Fair Value Measurements

The Partnership reports certain assets and liabilities at fair value, which is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). Under the accounting guidance for fair value measurements, inputs used to measure fair value are classified in one of three levels:

Level 1: Quoted market prices in active markets for identical assets or liabilities.

Level 2: Observable market-based inputs or unobservable inputs that are corroborated by market data.

Level 3: Unobservable inputs that are not corroborated by market data.

The Partnership has financial assets and liabilities subject to fair value measures. These financial assets and liabilities include cash and cash equivalents, accounts receivable, net, accounts payable and debt payable to Westlake, all of which are recorded at carrying value. The amounts reported in the consolidated balance sheets for accounts receivable, net and accounts payable approximate their fair value due to the short maturities of these instruments. The carrying and fair values of the Partnership's debt at JuneSeptember 30, 2022 and December 31, 2021 are summarized in the table below. The Partnership's debt includes the OpCo Revolver and the MLP Revolver at JuneSeptember 30, 2022. The fair value of debt is determined based on the present value of expected future cash flows using a discounted cash flow methodology. Because the Partnership's valuation methodology used for debt requires the use of significant unobservable inputs, the inputs used to measure the fair value of the Partnership's debt are classified as Level 3 within the fair value hierarchy. Inputs used to estimate the fair values of the Partnership's debt include the selection of an appropriate discount rate.